Methods for closed loop control of motor velocity of a surgical stapling and cutting instrument

ABSTRACT

A method of adjusting velocity in a motorized surgical instrument is provided. The surgical instrument comprises a displacement member configured to translate within the surgical instrument over a plurality of predefined zones, a motor coupled to the displacement member to translate the displacement member, a control circuit coupled to the motor, a position sensor coupled to the control circuit, the position sensor configured to measure the position of the displacement member and a timer circuit coupled to the control circuit, the timer circuit configured to measure elapsed time. The method includes setting a directed velocity of the displacement member; determining an actual velocity of the displacement member; determining an error between the directed velocity of the displacement member and the actual velocity of the displacement member; and controlling the actual velocity of the displacement member based on the magnitude of the error.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application claiming priority under35 U.S.C. § 120 to U.S. patent application Ser. No. 15/628,045, entitledMETHOD FOR CLOSED LOOP CONTROL OF MOTOR VELOCITY OF A SURGICAL STAPLINGAND CUTTING INSTRUMENT, filed Jun. 20, 2017, the entire disclosure ofwhich is hereby incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates to surgical instruments and, in variouscircumstances, to surgical stapling and cutting instruments and staplecartridges therefor that are designed to staple and cut tissue.

BACKGROUND

In a motorized surgical stapling and cutting instrument it may be usefulto control the velocity of a cutting member or to control thearticulation velocity of an end effector. Velocity of a displacementmember may be determined by measuring elapsed time at predeterminedposition intervals of the displacement member or measuring the positionof the displacement member at predetermined time intervals. The controlmay be open loop or closed loop. Such measurements may be useful toevaluate tissue conditions such as tissue thickness and adjust thevelocity of the cutting member during a firing stroke to account for thetissue conditions. Tissue thickness may be determined by comparingexpected velocity of the cutting member to the actual velocity of thecutting member. In some situations, it may be useful to articulate theend effector at a constant articulation velocity. In other situations,it may be useful to drive the end effector at a different articulationvelocity than a default articulation velocity at one or more regionswithin a sweep range of the end effector.

During use of a motorized surgical stapling and cutting instrument it ispossible that a velocity controlled system error may occur between thecommand or directed velocity and the actual measured velocity of thecutting member or firing member. Therefore, it may be desirable toprovide a closed loop feedback method of adjusting the velocity offiring based on the magnitude of one or more error terms based on thedifference between an actual velocity and a command or directed velocityover a specified increment of time/distance

SUMMARY

A method of adjusting velocity in a motorized surgical instrument isprovided. The surgical instrument comprises a displacement memberconfigured to translate within the surgical instrument over a pluralityof predefined zones, a motor coupled to the displacement member totranslate the displacement member, and a control circuit coupled to themotor. The surgical instrument further comprises a position sensorcoupled to the control circuit, the position sensor configured tomeasure the position of the displacement member and a timer circuitcoupled to the control circuit, the timer circuit configured to measureelapsed time. The method comprises setting, by the control circuit, adirected velocity of the displacement member; determining, by thecontrol circuit, an actual velocity of the displacement member;determining, by the control circuit, an error between the directedvelocity of the displacement member and the actual velocity of thedisplacement member; and controlling, by the control circuit, the actualvelocity of the displacement member based on the magnitude of the error.

FIGURES

The novel features of the aspects described herein are set forth withparticularity in the appended claims. These aspects, however, both as toorganization and methods of operation may be better understood byreference to the following description, taken in conjunction with theaccompanying drawings.

FIG. 1 is a perspective view of a surgical instrument that has aninterchangeable shaft assembly operably coupled thereto according to oneaspect of this disclosure.

FIG. 2 is an exploded assembly view of a portion of the surgicalinstrument of FIG. 1 according to one aspect of this disclosure.

FIG. 3 is an exploded assembly view of portions of the interchangeableshaft assembly according to one aspect of this disclosure.

FIG. 4 is an exploded view of an end effector of the surgical instrumentof FIG. 1 according to one aspect of this disclosure.

FIGS. 5A-5B is a block diagram of a control circuit of the surgicalinstrument of FIG. 1 spanning two drawing sheets according to one aspectof this disclosure.

FIG. 6 is a block diagram of the control circuit of the surgicalinstrument of FIG. 1 illustrating interfaces between the handleassembly, the power assembly, and the handle assembly and theinterchangeable shaft assembly according to one aspect of thisdisclosure.

FIG. 7 illustrates a control circuit configured to control aspects ofthe surgical instrument of FIG. 1 according to one aspect of thisdisclosure.

FIG. 8 illustrates a combinational logic circuit configured to controlaspects of the surgical instrument of FIG. 1 according to one aspect ofthis disclosure.

FIG. 9 illustrates a sequential logic circuit configured to controlaspects of the surgical instrument of FIG. 1 according to one aspect ofthis disclosure.

FIG. 10 is a diagram of an absolute positioning system of the surgicalinstrument of FIG. 1 where the absolute positioning system comprises acontrolled motor drive circuit arrangement comprising a sensorarrangement according to one aspect of this disclosure.

FIG. 11 is an exploded perspective view of the sensor arrangement for anabsolute positioning system showing a control circuit board assembly andthe relative alignment of the elements of the sensor arrangementaccording to one aspect of this disclosure.

FIG. 12 is a diagram of a position sensor comprising a magnetic rotaryabsolute positioning system according to one aspect of this disclosure.

FIG. 13 is a section view of an end effector of the surgical instrumentof FIG. 1 showing a firing member stroke relative to tissue graspedwithin the end effector according to one aspect of this disclosure.

FIG. 14 illustrates a block diagram of a surgical instrument programmedto control distal translation of a displacement member according to oneaspect of this disclosure.

FIG. 15 illustrates a diagram plotting two example displacement memberstrokes executed according to one aspect of this disclosure.

FIG. 16 is a graph depicting velocity (v) of a displacement member as afunction of displacement (δ) of the displacement member according to oneaspect of this disclosure.

FIG. 17 is a graph depicting velocity (v) of a displacement member as afunction of displacement (δ) of the displacement member according to oneaspect of this disclosure.

FIG. 18 is a graph of velocity (v) of a displacement member as afunction of displacement (δ) of the displacement member depictingcondition for threshold change of the directed velocity according to oneaspect of this disclosure.

FIG. 19 is a graph that illustrates the conditions for changing thedirected velocity 8506 of a displacement member according to one aspectof this disclosure.

FIG. 20 is a logic flow diagram of a process depicting a control programor a logic configuration for controlling velocity of a displacementmember based on the measured error between the directed velocity of adisplacement member and the actual velocity of the displacement memberaccording to one aspect of this disclosure.

FIG. 21 is a logic flow diagram of a process depicting a control programor a logic configuration for controlling velocity of a displacementmember based on the measured error between the directed velocity of adisplacement member and the actual velocity of the displacement memberaccording to one aspect of this disclosure.

FIG. 22 is a logic flow diagram of a process depicting a control programof logic configuration for controlling velocity of a displacement memberbased on the measured error between the directed velocity of adisplacement member and the actual velocity of the displacement memberaccording to one aspect of this disclosure.

FIG. 23A illustrates an end effector comprising a firing member coupledto an I-beam comprising a cutting edge according to one aspect of thisdisclosure.

FIG. 23B illustrates an end effector where the I-beam is located in atarget position at the top of a ramp with the top pin engaged in theT-slot according to one aspect of this disclosure.

FIG. 24 illustrates the I-beam firing stroke is illustrated by a chartaligned with the end effector according to one aspect of thisdisclosure.

FIG. 25 is a graphical depiction comparing I-beam stroke displacement asa function of time (top graph) and expected force-to-fire as a functionof time (bottom graph) according to one aspect of this disclosure.

FIG. 26 is a graphical depiction comparing tissue thickness as afunction of set displacement interval of I-beam stroke (top graph),force to fire as a function of set displacement interval of I-beamstroke (second graph from the top), dynamic time checks as a function ofset displacement interval of I-beam stroke (third graph from the top),and set velocity of I-beam as a function of set displacement interval ofI-beam stroke (bottom graph) according to one aspect of this disclosure.

FIG. 27 is a graphical depiction of force to fire as a function of timecomparing slow, medium and fast I-beam displacement velocities accordingto one aspect of this disclosure.

FIG. 28 is a logic flow diagram of a process depicting a control programor logic configuration for controlling command velocity in an initialfiring stage according to one aspect of this disclosure.

FIG. 29 is a logic flow diagram of a process depicting a control programor logic configuration for controlling command velocity in a dynamicfiring stage according to one aspect of this disclosure.

FIG. 30A illustrates an end effector comprising a firing member coupledto an I-beam comprising a cutting edge according to one aspect of thisdisclosure.

FIG. 30B illustrates an end effector where the I-beam is located in atarget position at the top of a ramp with the top pin engaged in theT-slot according to one aspect of this disclosure.

FIG. 31 illustrates the I-beam firing stroke is illustrated by a chartaligned with the end effector according to one aspect of thisdisclosure.

FIG. 32 is a graphical depiction comparing tissue thickness as afunction of set time interval of I-beam stroke (top graph), force tofire as a function of set time interval of I-beam stroke (second graphfrom the top), dynamic time checks as a function of set time interval ofI-beam stroke (third graph from the top), and set velocity of I-beam asa function of set time interval of I-beam stroke (bottom graph)according to one aspect of this disclosure.

FIG. 33 is a graphical depiction of force to fire as a function of timecomparing slow, medium and fast I-beam displacement velocities accordingto one aspect of this disclosure.

FIG. 34 is a logic flow diagram of a process depicting a control programor logic configuration for controlling command velocity in an initialfiring stage according to one aspect of this disclosure.

FIG. 35 is a logic flow diagram of a process depicting a control programor logic configuration for controlling command velocity in a dynamicfiring stage according to one aspect of this disclosure.

FIG. 36A illustrates an end effector comprising a firing member coupledto an I-beam comprising a cutting edge according to one aspect of thisdisclosure.

FIG. 36B illustrates an end effector where the I-beam is located in atarget position at the top of a ramp with the top pin engaged in theT-slot according to one aspect of this disclosure.

FIG. 37 illustrates a screw drive system 10470 that may be employed withthe surgical instrument 10 (FIG. 1) according to one aspect of thisdisclosure.

FIG. 38 illustrates the I-beam firing stroke is illustrated by a chartaligned with the end effector according to one aspect of thisdisclosure.

FIG. 39 is a graphical depiction comparing I-beam stroke displacement asa function of time (top graph) and expected force-to-fire as a functionof time (bottom graph) according to one aspect of this disclosure.

FIG. 40 is a graphical depiction comparing tissue thickness as afunction of set rotation interval of I-beam stroke (top graph), force tofire as a function of set rotation interval of I-beam stroke (secondgraph from the top), dynamic time checks as a function of set rotationinterval of I-beam stroke (third graph from the top), and set velocityof I-beam as a function of set rotation interval of I-beam stroke(bottom graph) according to one aspect of this disclosure.

FIG. 41 is a graphical depiction of force to fire as a function of timecomparing slow, medium and fast I-beam displacement velocities accordingto one aspect of this disclosure.

FIG. 42 is a logic flow diagram of a process depicting a control programor logic configuration for controlling command velocity in an initialfiring stage according to one aspect of this disclosure.

FIG. 43 is a logic flow diagram of a process depicting a control programor logic configuration for controlling command velocity in a dynamicfiring stage according to one aspect of this disclosure.

FIG. 44 is a perspective view of a surgical instrument according to oneaspect of this disclosure.

FIG. 45 is a detail view of a display portion of the surgical instrumentshown in FIG. 44 according to one aspect of this disclosure.

FIG. 46 is a logic flow diagram of a process depicting a control programor logic configuration for controlling a display according to one aspectof this disclosure.

FIG. 47 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 48 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 49 is a display depicting a velocity feedback screen indicative ofan automatic mode according to one aspect of this disclosure.

FIG. 50 is a display depicting a velocity feedback screen indicative ofan automatic mode according to one aspect of this disclosure.

FIG. 51 is a display depicting a velocity feedback screen indicative ofan automatic mode according to one aspect of this disclosure.

FIG. 52 is a display depicting a velocity feedback screen indicative ofan automatic mode according to one aspect of this disclosure.

FIG. 53 is a display depicting a velocity feedback screen indicative ofa manual mode according to one aspect of this disclosure.

FIG. 54 is a display depicting a velocity feedback screen indicative ofa manual mode according to one aspect of this disclosure.

FIG. 55 is a display depicting a velocity feedback screen indicative ofan automatic mode according to one aspect of this disclosure.

FIG. 56 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 57 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 58 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 59 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 60 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 61 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 62 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 63 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 64 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 65 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 66 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 67 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 68 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 69 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 70 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 71 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 72 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 73 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 74 is a display depicting a velocity feedback screen indicative ofa command velocity and an actual velocity according to one aspect ofthis disclosure.

FIG. 75 is a display depicting a velocity feedback screen indicative ofa command velocity and an actual velocity according to one aspect ofthis disclosure.

FIG. 76 is a display depicting a velocity feedback screen indicative ofa command velocity and an actual velocity according to one aspect ofthis disclosure.

FIG. 77 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 78 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 79 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 80 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 81 is a display depicting a temperature feedback screen accordingto one aspect of this disclosure.

FIG. 82 is a perspective view of a surgical instrument according to oneaspect of this disclosure.

FIG. 83 is a detail view of a display portion of the surgical instrumentshown in FIG. 82 according to one aspect of this disclosure.

FIG. 84 is a logic flow diagram of a process depicting a control programor logic configuration for controlling a display according to one aspectof this disclosure.

FIG. 85 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 86 is a display depicting a velocity feedback screen according toone aspect of this disclosure.

FIG. 87 is a switch located on the housing of the surgical instrumentshown in FIG. 82.

FIG. 88 is a chart representing various manners of how the displayhighlights selection menu options.

FIG. 89 is a display depicting a velocity feedback screen indicative ofa manual fast mode according to one aspect of this disclosure.

FIG. 90 is a display depicting a velocity feedback screen indicative ofa manual fast mode according to one aspect of this disclosure.

FIG. 91 is a display depicting a velocity feedback screen indicative ofa manual fast mode according to one aspect of this disclosure.

FIG. 92 is a logic flow diagram of a process depicting a control programor logic configuration for controlling motor velocity based on batterycondition according to one aspect of this disclosure.

FIG. 93 is a logic flow diagram of a process depicting a control programor logic configuration for controlling motor velocity based on stalledcondition during a normal firing cycle according to one aspect of thisdisclosure.

FIG. 94 is a logic flow diagram of a process depicting a control programor logic configuration for controlling motor velocity while in manualmode according to one aspect of this disclosure.

FIG. 95 is a logic flow diagram of a process depicting a control programor logic configuration for controlling motor velocity based on stalledcondition during a normal firing cycle and implementing a forced pausein the firing cycle according to one aspect of this disclosure.

FIG. 96 is a logic flow diagram of a process depicting a control programor logic configuration for controlling motor velocity based on stalledcondition during a normal firing and reducing the velocity one levelonce the firing cycle is restarted according to one aspect of thisdisclosure.

FIG. 97 is a logic flow diagram of a process depicting a control programor logic configuration for controlling motor velocity based on stalledcondition during a normal firing cycle in manual mode and reducingvelocity one level once the firing cycle is restarted according to oneaspect of this disclosure.

FIG. 98 is a logic flow diagram of a process depicting a control programor logic configuration for controlling motor velocity based on stalledcondition during a normal firing cycle and pausing the firing cycleuntil the user releases the firing trigger according to one aspect ofthis disclosure.

FIG. 99 is a logic flow diagram of a process depicting a control programor logic configuration for controlling motor velocity during transitionbetween velocities according to one aspect of this disclosure.

FIG. 100 is a logic flow diagram depicting a process of a controlprogram or a logic configuration for adjusting the velocity of adisplacement member based on the magnitude of one or more error termsbased on the difference between an actual velocity of the displacementmember and a command or directed velocity of the displacement memberover a specified increment of time or distance according to one aspectof this disclosure.

DESCRIPTION

Applicant of the present application owns the following patentapplications filed on Jun. 20, 2017 and which are each hereinincorporated by reference in their respective entireties:

U.S. patent application Ser. No. 15/627,998, titled CONTROL OF MOTORVELOCITY OF A SURGICAL STAPLING AND CUTTING INSTRUMENT BASED ON ANGLE OFARTICULATION, by inventors Frederick E. Shelton, I V et al., filed Jun.20, 2017.

U.S. patent application Ser. No. 15/628,019, titled SURGICAL INSTRUMENTWITH VARIABLE DURATION TRIGGER ARRANGEMENT, by inventors Frederick E.Shelton, I V et al., filed Jun. 20, 2017.

U.S. patent application Ser. No. 15/628,036, titled SYSTEMS AND METHODSFOR CONTROLLING DISPLACEMENT MEMBER MOTION OF A SURGICAL STAPLING ANDCUTTING INSTRUMENT, by inventors Frederick E. Shelton, I V et al., filedJun. 20, 2017.

U.S. patent application Ser. No. 15/628,050, titled SYSTEMS AND METHODSFOR CONTROLLING MOTOR VELOCITY OF A SURGICAL STAPLING AND CUTTINGINSTRUMENT ACCORDING TO ARTICULATION ANGLE OF END EFFECTOR, by inventorsFrederick E. Shelton, I V et al., filed Jun. 20, 2017.

U.S. patent application Ser. No. 15/628,075, titled SYSTEMS AND METHODSFOR CONTROLLING MOTOR VELOCITY OF A SURGICAL STAPLING AND CUTTINGINSTRUMENT, by inventors Frederick E. Shelton, I V et al., filed Jun.20, 2017.

U.S. patent application Ser. No. 15/628,154, titled SURGICAL INSTRUMENTHAVING CONTROLLABLE ARTICULATION VELOCITY, by inventors Frederick E.Shelton, I V et al., filed Jun. 20, 2017.

U.S. patent application Ser. No. 15/628,158, titled SYSTEMS AND METHODSFOR CONTROLLING VELOCITY OF A DISPLACEMENT MEMBER OF A SURGICAL STAPLINGAND CUTTING INSTRUMENT, by inventors Frederick E. Shelton, I V et al.,filed Jun. 20, 2017.

U.S. patent application Ser. No. 15/628,162, titled SYSTEMS AND METHODSFOR CONTROLLING DISPLACEMENT MEMBER VELOCITY FOR A SURGICAL INSTRUMENT,by inventors Frederick E. Shelton, I V et al., filed Jun. 20, 2017.

U.S. patent application Ser. No. 15/628,168, titled CONTROL OF MOTORVELOCITY OF A SURGICAL STAPLING AND CUTTING INSTRUMENT BASED ON ANGLE OFARTICULATION, by inventors Frederick E. Shelton, I V et al., filed Jun.20, 2017.

U.S. patent application Ser. No. 15/628,175, titled TECHNIQUES FORADAPTIVE CONTROL OF MOTOR VELOCITY OF A SURGICAL STAPLING AND CUTTINGINSTRUMENT, by inventors Frederick E. Shelton, I V et al., filed Jun.20, 2017.

U.S. patent application Ser. No. 15/628,053, titled CLOSED LOOP FEEDBACKCONTROL OF MOTOR VELOCITY OF A SURGICAL STAPLING AND CUTTING INSTRUMENTBASED ON MAGNITUDE OF VELOCITY ERROR MEASUREMENTS, by inventors RaymondE. Parfett et al., filed Jun. 20, 2017.

U.S. patent application Ser. No. 15/628,060, titled CLOSED LOOP FEEDBACKCONTROL OF MOTOR VELOCITY OF A SURGICAL STAPLING AND CUTTING INSTRUMENTBASED ON MEASURED TIME OVER A SPECIFIED DISPLACEMENT DISTANCE, byinventors Jason L. Harris et al., filed Jun. 20, 2017.

U.S. patent application Ser. No. 15/628,067, titled CLOSED LOOP FEEDBACKCONTROL OF MOTOR VELOCITY OF A SURGICAL STAPLING AND CUTTING INSTRUMENTBASED ON MEASURED DISPLACEMENT DISTANCE TRAVELED OVER A SPECIFIED TIMEINTERVAL, by inventors Frederick E. Shelton, I V et al., filed Jun. 20,2017.

U.S. patent application Ser. No. 15/628,072, titled CLOSED LOOP FEEDBACKCONTROL OF MOTOR VELOCITY OF A SURGICAL STAPLING AND CUTTING INSTRUMENTBASED ON MEASURED TIME OVER A SPECIFIED NUMBER OF SHAFT ROTATIONS, byinventors Frederick E. Shelton, I V et al., filed Jun. 20, 2017.

U.S. patent application Ser. No. 15/628,029, titled SYSTEMS AND METHODSFOR CONTROLLING DISPLAYING MOTOR VELOCITY FOR A SURGICAL INSTRUMENT, byinventors Jason L. Harris et al., filed Jun. 20, 2017.

U.S. patent application Ser. No. 15/628,077, titled SYSTEMS AND METHODSFOR CONTROLLING MOTOR SPEED ACCORDING TO USER INPUT FOR A SURGICALINSTRUMENT, by inventors Jason L. Harris et al., filed Jun. 20, 2017.

U.S. patent application Ser. No. 15/628,115, titled CLOSED LOOP FEEDBACKCONTROL OF MOTOR VELOCITY OF A SURGICAL STAPLING AND CUTTING INSTRUMENTBASED ON SYSTEM CONDITIONS, by inventors Frederick E. Shelton, I V etal., filed Jun. 20, 2017.

U.S. Design patent application Ser. No. 29/608,238, titled GRAPHICALUSER INTERFACE FOR A DISPLAY OR PORTION THEREOF, by inventors Jason L.Harris et al., filed Jun. 20, 2017.

U.S. Design patent application Ser. No. 29/608,231, titled GRAPHICALUSER INTERFACE FOR A DISPLAY OR PORTION THEREOF, by inventors Jason L.Harris et al., filed Jun. 20, 2017.

U.S. Design patent application Ser. No. 29/608,246, titled GRAPHICALUSER INTERFACE FOR A DISPLAY OR PORTION THEREOF, by inventors FrederickE. Shelton, I V et al., filed Jun. 20, 2017.

Applicant of the present application owns the following U.S. Designpatent applications filed on Jun. 20, 2017 and which are each hereinincorporated by reference in their respective entireties:

U.S. Design patent application Ser. No. 29/608,238, titled GRAPHICALUSER INTERFACE FOR A DISPLAY OR PORTION THEREOF, by inventors Jason L.Harris et al., filed Jun. 20, 2017.

U.S. Design patent application Ser. No. 29/608,231, titled GRAPHICALUSER INTERFACE FOR A DISPLAY OR PORTION THEREOF, by inventors Jason L.Harris et al., filed Jun. 20, 2017.

U.S. Design patent application Ser. No. 29/608,231, titled GRAPHICALUSER INTERFACE FOR A DISPLAY OR PORTION THEREOF, by inventors FrederickE. Shelton, I V et al., filed Jun. 20, 2017.

Certain aspects are shown and described to provide an understanding ofthe structure, function, manufacture, and use of the disclosed devicesand methods. Features shown or described in one example may be combinedwith features of other examples and modifications and variations arewithin the scope of this disclosure.

The terms “proximal” and “distal” are relative to a clinicianmanipulating the handle of the surgical instrument where “proximal”refers to the portion closer to the clinician and “distal” refers to theportion located further from the clinician. For expediency, spatialterms “vertical,” “horizontal,” “up,” and “down” used with respect tothe drawings are not intended to be limiting and/or absolute, becausesurgical instruments can used in many orientations and positions.

Example devices and methods are provided for performing laparoscopic andminimally invasive surgical procedures. Such devices and methods,however, can be used in other surgical procedures and applicationsincluding open surgical procedures, for example. The surgicalinstruments can be inserted into a through a natural orifice or throughan incision or puncture hole formed in tissue. The working portions orend effector portions of the instruments can be inserted directly intothe body or through an access device that has a working channel throughwhich the end effector and elongated shaft of the surgical instrumentcan be advanced.

FIGS. 1-4 depict a motor-driven surgical instrument 10 for cutting andfastening that may or may not be reused. In the illustrated examples,the surgical instrument 10 includes a housing 12 that comprises a handleassembly 14 that is configured to be grasped, manipulated, and actuatedby the clinician. The housing 12 is configured for operable attachmentto an interchangeable shaft assembly 200 that has an end effector 300operably coupled thereto that is configured to perform one or moresurgical tasks or procedures. In accordance with the present disclosure,various forms of interchangeable shaft assemblies may be effectivelyemployed in connection with robotically controlled surgical systems. Theterm “housing” may encompass a housing or similar portion of a roboticsystem that houses or otherwise operably supports at least one drivesystem configured to generate and apply at least one control motion thatcould be used to actuate interchangeable shaft assemblies. The term“frame” may refer to a portion of a handheld surgical instrument. Theterm “frame” also may represent a portion of a robotically controlledsurgical instrument and/or a portion of the robotic system that may beused to operably control a surgical instrument. Interchangeable shaftassemblies may be employed with various robotic systems, instruments,components, and methods disclosed in U.S. Pat. No. 9,072,535, entitledSURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENTARRANGEMENTS, which is herein incorporated by reference in its entirety.

FIG. 1 is a perspective view of a surgical instrument 10 that has aninterchangeable shaft assembly 200 operably coupled thereto according toone aspect of this disclosure. The housing 12 includes an end effector300 that comprises a surgical cutting and fastening device configured tooperably support a surgical staple cartridge 304 therein. The housing 12may be configured for use in connection with interchangeable shaftassemblies that include end effectors that are adapted to supportdifferent sizes and types of staple cartridges, have different shaftlengths, sizes, and types. The housing 12 may be employed with a varietyof interchangeable shaft assemblies, including assemblies configured toapply other motions and forms of energy such as, radio frequency (RF)energy, ultrasonic energy, and/or motion to end effector arrangementsadapted for use in connection with various surgical applications andprocedures. The end effectors, shaft assemblies, handles, surgicalinstruments, and/or surgical instrument systems can utilize any suitablefastener, or fasteners, to fasten tissue. For instance, a fastenercartridge comprising a plurality of fasteners removably stored thereincan be removably inserted into and/or attached to the end effector of ashaft assembly.

The handle assembly 14 may comprise a pair of interconnectable handlehousing segments 16, 18 interconnected by screws, snap features,adhesive, etc. The handle housing segments 16, 18 cooperate to form apistol grip portion 19 that can be gripped and manipulated by theclinician. The handle assembly 14 operably supports a plurality of drivesystems configured to generate and apply control motions tocorresponding portions of the interchangeable shaft assembly that isoperably attached thereto. A display may be provided below a cover 45.

FIG. 2 is an exploded assembly view of a portion of the surgicalinstrument 10 of FIG. 1 according to one aspect of this disclosure. Thehandle assembly 14 may include a frame 20 that operably supports aplurality of drive systems. The frame 20 can operably support a “first”or closure drive system 30, which can apply closing and opening motionsto the interchangeable shaft assembly 200. The closure drive system 30may include an actuator such as a closure trigger 32 pivotally supportedby the frame 20. The closure trigger 32 is pivotally coupled to thehandle assembly 14 by a pivot pin 33 to enable the closure trigger 32 tobe manipulated by a clinician. When the clinician grips the pistol gripportion 19 of the handle assembly 14, the closure trigger 32 can pivotfrom a starting or “unactuated” position to an “actuated” position andmore particularly to a fully compressed or fully actuated position.

The handle assembly 14 and the frame 20 may operably support a firingdrive system 80 configured to apply firing motions to correspondingportions of the interchangeable shaft assembly attached thereto. Thefiring drive system 80 may employ an electric motor 82 located in thepistol grip portion 19 of the handle assembly 14. The electric motor 82may be a DC brushed motor having a maximum rotational speed ofapproximately 25,000 RPM, for example. In other arrangements, the motormay include a brushless motor, a cordless motor, a synchronous motor, astepper motor, or any other suitable electric motor. The electric motor82 may be powered by a power source 90 that may comprise a removablepower pack 92. The removable power pack 92 may comprise a proximalhousing portion 94 configured to attach to a distal housing portion 96.The proximal housing portion 94 and the distal housing portion 96 areconfigured to operably support a plurality of batteries 98 therein.Batteries 98 may each comprise, for example, a Lithium Ion (LI) or othersuitable battery. The distal housing portion 96 is configured forremovable operable attachment to a control circuit board 100, which isoperably coupled to the electric motor 82. Several batteries 98connected in series may power the surgical instrument 10. The powersource 90 may be replaceable and/or rechargeable. A display 43, which islocated below the cover 45, is electrically coupled to the controlcircuit board 100. The cover 45 may be removed to expose the display 43.

The electric motor 82 can include a rotatable shaft (not shown) thatoperably interfaces with a gear reducer assembly 84 mounted in meshingengagement with a with a set, or rack, of drive teeth 122 on alongitudinally movable drive member 120. The longitudinally movabledrive member 120 has a rack of drive teeth 122 formed thereon formeshing engagement with a corresponding drive gear 86 of the gearreducer assembly 84.

In use, a voltage polarity provided by the power source 90 can operatethe electric motor 82 in a clockwise direction wherein the voltagepolarity applied to the electric motor by the battery can be reversed inorder to operate the electric motor 82 in a counter-clockwise direction.When the electric motor 82 is rotated in one direction, thelongitudinally movable drive member 120 will be axially driven in thedistal direction “DD.” When the electric motor 82 is driven in theopposite rotary direction, the longitudinally movable drive member 120will be axially driven in a proximal direction “PD.” The handle assembly14 can include a switch that can be configured to reverse the polarityapplied to the electric motor 82 by the power source 90. The handleassembly 14 may include a sensor configured to detect the position ofthe longitudinally movable drive member 120 and/or the direction inwhich the longitudinally movable drive member 120 is being moved.

Actuation of the electric motor 82 can be controlled by a firing trigger130 that is pivotally supported on the handle assembly 14. The firingtrigger 130 may be pivoted between an unactuated position and anactuated position.

Turning back to FIG. 1, the interchangeable shaft assembly 200 includesan end effector 300 comprising an elongated channel 302 configured tooperably support a surgical staple cartridge 304 therein. The endeffector 300 may include an anvil 306 that is pivotally supportedrelative to the elongated channel 302. The interchangeable shaftassembly 200 may include an articulation joint 270. Construction andoperation of the end effector 300 and the articulation joint 270 are setforth in U.S. Patent Application Publication No. 2014/0263541, entitledARTICULATABLE SURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK, whichis herein incorporated by reference in its entirety. The interchangeableshaft assembly 200 may include a proximal housing or nozzle 201comprised of nozzle portions 202, 203. The interchangeable shaftassembly 200 may include a closure tube 260 extending along a shaft axisSA that can be utilized to close and/or open the anvil 306 of the endeffector 300.

Turning back to FIG. 1, the closure tube 260 is translated distally(direction “DD”) to close the anvil 306, for example, in response to theactuation of the closure trigger 32 in the manner described in theaforementioned reference U.S. Patent Application Publication No.2014/0263541. The anvil 306 is opened by proximally translating theclosure tube 260. In the anvil-open position, the closure tube 260 ismoved to its proximal position.

FIG. 3 is another exploded assembly view of portions of theinterchangeable shaft assembly 200 according to one aspect of thisdisclosure. The interchangeable shaft assembly 200 may include a firingmember 220 supported for axial travel within the spine 210. The firingmember 220 includes an intermediate firing shaft 222 configured toattach to a distal cutting portion or knife bar 280. The firing member220 may be referred to as a “second shaft” or a “second shaft assembly”.The intermediate firing shaft 222 may include a longitudinal slot 223 ina distal end configured to receive a tab 284 on the proximal end 282 ofthe knife bar 280. The longitudinal slot 223 and the proximal end 282may be configured to permit relative movement there between and cancomprise a slip joint 286. The slip joint 286 can permit theintermediate firing shaft 222 of the firing member 220 to articulate theend effector 300 about the articulation joint 270 without moving, or atleast substantially moving, the knife bar 280. Once the end effector 300has been suitably oriented, the intermediate firing shaft 222 can beadvanced distally until a proximal sidewall of the longitudinal slot 223contacts the tab 284 to advance the knife bar 280 and fire the staplecartridge positioned within the channel 302. The spine 210 has anelongated opening or window 213 therein to facilitate assembly andinsertion of the intermediate firing shaft 222 into the spine 210. Oncethe intermediate firing shaft 222 has been inserted therein, a top framesegment 215 may be engaged with the shaft frame 212 to enclose theintermediate firing shaft 222 and knife bar 280 therein. Operation ofthe firing member 220 may be found in U.S. Patent ApplicationPublication No. 2014/0263541. A spine 210 can be configured to slidablysupport a firing member 220 and the closure tube 260 that extends aroundthe spine 210. The spine 210 may slidably support an articulation driver230.

The interchangeable shaft assembly 200 can include a clutch assembly 400configured to selectively and releasably couple the articulation driver230 to the firing member 220. The clutch assembly 400 includes a lockcollar, or lock sleeve 402, positioned around the firing member 220wherein the lock sleeve 402 can be rotated between an engaged positionin which the lock sleeve 402 couples the articulation driver 230 to thefiring member 220 and a disengaged position in which the articulationdriver 230 is not operably coupled to the firing member 220. When thelock sleeve 402 is in the engaged position, distal movement of thefiring member 220 can move the articulation driver 230 distally and,correspondingly, proximal movement of the firing member 220 can move thearticulation driver 230 proximally. When the lock sleeve 402 is in thedisengaged position, movement of the firing member 220 is nottransmitted to the articulation driver 230 and, as a result, the firingmember 220 can move independently of the articulation driver 230. Thenozzle 201 may be employed to operably engage and disengage thearticulation drive system with the firing drive system in the variousmanners described in U.S. Patent Application Publication No.2014/0263541.

The interchangeable shaft assembly 200 can comprise a slip ring assembly600 which can be configured to conduct electrical power to and/or fromthe end effector 300 and/or communicate signals to and/or from the endeffector 300, for example. The slip ring assembly 600 can comprise aproximal connector flange 604 and a distal connector flange 601positioned within a slot defined in the nozzle portions 202, 203. Theproximal connector flange 604 can comprise a first face and the distalconnector flange 601 can comprise a second face positioned adjacent toand movable relative to the first face. The distal connector flange 601can rotate relative to the proximal connector flange 604 about the shaftaxis SA-SA (FIG. 1). The proximal connector flange 604 can comprise aplurality of concentric, or at least substantially concentric,conductors 602 defined in the first face thereof. A connector 607 can bemounted on the proximal side of the distal connector flange 601 and mayhave a plurality of contacts wherein each contact corresponds to and isin electrical contact with one of the conductors 602. Such anarrangement permits relative rotation between the proximal connectorflange 604 and the distal connector flange 601 while maintainingelectrical contact there between. The proximal connector flange 604 caninclude an electrical connector 606 that can place the conductors 602 insignal communication with a shaft circuit board, for example. In atleast one instance, a wiring harness comprising a plurality ofconductors can extend between the electrical connector 606 and the shaftcircuit board. The electrical connector 606 may extend proximallythrough a connector opening defined in the chassis mounting flange. U.S.Patent Application Publication No. 2014/0263551, entitled STAPLECARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, is incorporated herein byreference in its entirety. U.S. Patent Application Publication No.2014/0263552, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM,is incorporated by reference in its entirety. Further details regardingslip ring assembly 600 may be found in U.S. Patent ApplicationPublication No. 2014/0263541.

The interchangeable shaft assembly 200 can include a proximal portionfixably mounted to the handle assembly 14 and a distal portion that isrotatable about a longitudinal axis. The rotatable distal shaft portioncan be rotated relative to the proximal portion about the slip ringassembly 600. The distal connector flange 601 of the slip ring assembly600 can be positioned within the rotatable distal shaft portion.

FIG. 4 is an exploded view of one aspect of an end effector 300 of thesurgical instrument 10 of FIG. 1 according to one aspect of thisdisclosure. The end effector 300 may include the anvil 306 and thesurgical staple cartridge 304. The anvil 306 may be coupled to anelongated channel 302. Apertures 199 can be defined in the elongatedchannel 302 to receive pins 152 extending from the anvil 306 to allowthe anvil 306 to pivot from an open position to a closed positionrelative to the elongated channel 302 and surgical staple cartridge 304.A firing bar 172 is configured to longitudinally translate into the endeffector 300. The firing bar 172 may be constructed from one solidsection, or may include a laminate material comprising a stack of steelplates. The firing bar 172 comprises an I-beam 178 and a cutting edge182 at a distal end thereof. A distally projecting end of the firing bar172 can be attached to the I-beam 178 to assist in spacing the anvil 306from a surgical staple cartridge 304 positioned in the elongated channel302 when the anvil 306 is in a closed position. The I-beam 178 mayinclude a sharpened cutting edge 182 to sever tissue as the I-beam 178is advanced distally by the firing bar 172. In operation, the I-beam 178may, or fire, the surgical staple cartridge 304. The surgical staplecartridge 304 can include a molded cartridge body 194 that holds aplurality of staples 191 resting upon staple drivers 192 withinrespective upwardly open staple cavities 195. A wedge sled 190 is drivendistally by the I-beam 178, sliding upon a cartridge tray 196 of thesurgical staple cartridge 304. The wedge sled 190 upwardly cams thestaple drivers 192 to force out the staples 191 into deforming contactwith the anvil 306 while the cutting edge 182 of the I-beam 178 seversclamped tissue.

The I-beam 178 can include upper pins 180 that engage the anvil 306during firing. The I-beam 178 may include middle pins 184 and a bottomfoot 186 to engage portions of the cartridge body 194, cartridge tray196, and elongated channel 302. When a surgical staple cartridge 304 ispositioned within the elongated channel 302, a slot 193 defined in thecartridge body 194 can be aligned with a longitudinal slot 197 definedin the cartridge tray 196 and a slot 189 defined in the elongatedchannel 302. In use, the I-beam 178 can slide through the alignedlongitudinal slots 193, 197, and 189 wherein, as indicated in FIG. 4,the bottom foot 186 of the I-beam 178 can engage a groove running alongthe bottom surface of elongated channel 302 along the length of slot189, the middle pins 184 can engage the top surfaces of cartridge tray196 along the length of longitudinal slot 197, and the upper pins 180can engage the anvil 306. The I-beam 178 can space, or limit therelative movement between, the anvil 306 and the surgical staplecartridge 304 as the firing bar 172 is advanced distally to fire thestaples from the surgical staple cartridge 304 and/or incise the tissuecaptured between the anvil 306 and the surgical staple cartridge 304.The firing bar 172 and the I-beam 178 can be retracted proximallyallowing the anvil 306 to be opened to release the two stapled andsevered tissue portions.

FIGS. 5A-5B is a block diagram of a control circuit 700 of the surgicalinstrument 10 of FIG. 1 spanning two drawing sheets according to oneaspect of this disclosure. Referring primarily to FIGS. 5A-5B, a handleassembly 702 may include a motor 714 which can be controlled by a motordriver 715 and can be employed by the firing system of the surgicalinstrument 10. In various forms, the motor 714 may be a DC brusheddriving motor having a maximum rotational speed of approximately 25,000RPM. In other arrangements, the motor 714 may include a brushless motor,a cordless motor, a synchronous motor, a stepper motor, or any othersuitable electric motor. The motor driver 715 may comprise an H-Bridgedriver comprising field-effect transistors (FETs) 719, for example. Themotor 714 can be powered by the power assembly 706 releasably mounted tothe handle assembly 200 for supplying control power to the surgicalinstrument 10. The power assembly 706 may comprise a battery which mayinclude a number of battery cells connected in series that can be usedas the power source to power the surgical instrument 10. In certaincircumstances, the battery cells of the power assembly 706 may bereplaceable and/or rechargeable. In at least one example, the batterycells can be Lithium-Ion batteries which can be separably couplable tothe power assembly 706.

The shaft assembly 704 may include a shaft assembly controller 722 whichcan communicate with a safety controller and power management controller716 through an interface while the shaft assembly 704 and the powerassembly 706 are coupled to the handle assembly 702. For example, theinterface may comprise a first interface portion 725 which may includeone or more electric connectors for coupling engagement withcorresponding shaft assembly electric connectors and a second interfaceportion 727 which may include one or more electric connectors forcoupling engagement with corresponding power assembly electricconnectors to permit electrical communication between the shaft assemblycontroller 722 and the power management controller 716 while the shaftassembly 704 and the power assembly 706 are coupled to the handleassembly 702. One or more communication signals can be transmittedthrough the interface to communicate one or more of the powerrequirements of the attached interchangeable shaft assembly 704 to thepower management controller 716. In response, the power managementcontroller may modulate the power output of the battery of the powerassembly 706, as described below in greater detail, in accordance withthe power requirements of the attached shaft assembly 704. Theconnectors may comprise switches which can be activated after mechanicalcoupling engagement of the handle assembly 702 to the shaft assembly 704and/or to the power assembly 706 to allow electrical communicationbetween the shaft assembly controller 722 and the power managementcontroller 716.

The interface can facilitate transmission of the one or morecommunication signals between the power management controller 716 andthe shaft assembly controller 722 by routing such communication signalsthrough a main controller 717 residing in the handle assembly 702, forexample. In other circumstances, the interface can facilitate a directline of communication between the power management controller 716 andthe shaft assembly controller 722 through the handle assembly 702 whilethe shaft assembly 704 and the power assembly 706 are coupled to thehandle assembly 702.

The main controller 717 may be any single core or multicore processorsuch as those known under the trade name ARM Cortex by TexasInstruments. In one aspect, the main controller 717 may be anLM4F230H5QR ARM Cortex-M4F Processor Core, available from TexasInstruments, for example, comprising on-chip memory of 256 KBsingle-cycle flash memory, or other non-volatile memory, up to 40 MHz, aprefetch buffer to improve performance above 40 MHz, a 32 KBsingle-cycle serial random access memory (SRAM), internal read-onlymemory (ROM) loaded with StellarisWare® software, 2 KB electricallyerasable programmable read-only memory (EEPROM), one or more pulse widthmodulation (PWM) modules, one or more quadrature encoder inputs (QEI)analog, one or more 12-bit Analog-to-Digital Converters (ADC) with 12analog input channels, details of which are available for the productdatasheet.

The safety controller may be a safety controller platform comprising twocontroller-based families such as TMS570 and RM4x known under the tradename Hercules ARM Cortex R4, also by Texas Instruments. The safetycontroller may be configured specifically for IEC 61508 and ISO 26262safety critical applications, among others, to provide advancedintegrated safety features while delivering scalable performance,connectivity, and memory options.

The power assembly 706 may include a power management circuit which maycomprise the power management controller 716, a power modulator 738, anda current sense circuit 736. The power management circuit can beconfigured to modulate power output of the battery based on the powerrequirements of the shaft assembly 704 while the shaft assembly 704 andthe power assembly 706 are coupled to the handle assembly 702. The powermanagement controller 716 can be programmed to control the powermodulator 738 of the power output of the power assembly 706 and thecurrent sense circuit 736 can be employed to monitor power output of thepower assembly 706 to provide feedback to the power managementcontroller 716 about the power output of the battery so that the powermanagement controller 716 may adjust the power output of the powerassembly 706 to maintain a desired output. The power managementcontroller 716 and/or the shaft assembly controller 722 each maycomprise one or more processors and/or memory units which may store anumber of software modules.

The surgical instrument 10 (FIGS. 1-4) may comprise an output device 742which may include devices for providing a sensory feedback to a user.Such devices may comprise, for example, visual feedback devices (e.g.,an LCD display screen, LED indicators), audio feedback devices (e.g., aspeaker, a buzzer) or tactile feedback devices (e.g., haptic actuators).In certain circumstances, the output device 742 may comprise a display743 which may be included in the handle assembly 702. The shaft assemblycontroller 722 and/or the power management controller 716 can providefeedback to a user of the surgical instrument 10 through the outputdevice 742. The interface can be configured to connect the shaftassembly controller 722 and/or the power management controller 716 tothe output device 742. The output device 742 can instead be integratedwith the power assembly 706. In such circumstances, communicationbetween the output device 742 and the shaft assembly controller 722 maybe accomplished through the interface while the shaft assembly 704 iscoupled to the handle assembly 702.

The control circuit 700 comprises circuit segments configured to controloperations of the powered surgical instrument 10. A safety controllersegment (Segment 1) comprises a safety controller and the maincontroller 717 segment (Segment 2). The safety controller and/or themain controller 717 are configured to interact with one or moreadditional circuit segments such as an acceleration segment, a displaysegment, a shaft segment, an encoder segment, a motor segment, and apower segment. Each of the circuit segments may be coupled to the safetycontroller and/or the main controller 717. The main controller 717 isalso coupled to a flash memory. The main controller 717 also comprises aserial communication interface. The main controller 717 comprises aplurality of inputs coupled to, for example, one or more circuitsegments, a battery, and/or a plurality of switches. The segmentedcircuit may be implemented by any suitable circuit, such as, forexample, a printed circuit board assembly (PCBA) within the poweredsurgical instrument 10. It should be understood that the term processoras used herein includes any microprocessor, processors, controller,controllers, or other basic computing device that incorporates thefunctions of a computer's central processing unit (CPU) on an integratedcircuit or at most a few integrated circuits. The main controller 717 isa multipurpose, programmable device that accepts digital data as input,processes it according to instructions stored in its memory, andprovides results as output. It is an example of sequential digitallogic, as it has internal memory. The control circuit 700 can beconfigured to implement one or more of the processes described herein.

The acceleration segment (Segment 3) comprises an accelerometer. Theaccelerometer is configured to detect movement or acceleration of thepowered surgical instrument 10. Input from the accelerometer may be usedto transition to and from a sleep mode, identify an orientation of thepowered surgical instrument, and/or identify when the surgicalinstrument has been dropped. In some examples, the acceleration segmentis coupled to the safety controller and/or the main controller 717.

The display segment (Segment 4) comprises a display connector coupled tothe main controller 717. The display connector couples the maincontroller 717 to a display through one or more integrated circuitdrivers of the display. The integrated circuit drivers of the displaymay be integrated with the display and/or may be located separately fromthe display. The display may comprise any suitable display, such as, forexample, an organic light-emitting diode (OLED) display, aliquid-crystal display (LCD), and/or any other suitable display. In someexamples, the display segment is coupled to the safety controller.

The shaft segment (Segment 5) comprises controls for an interchangeableshaft assembly 200 (FIGS. 1 and 3) coupled to the surgical instrument 10(FIGS. 1-4) and/or one or more controls for an end effector 300 coupledto the interchangeable shaft assembly 200. The shaft segment comprises ashaft connector configured to couple the main controller 717 to a shaftPCBA. The shaft PCBA comprises a low-power microcontroller with aferroelectric random access memory (FRAM), an articulation switch, ashaft release Hall effect switch, and a shaft PCBA EEPROM. The shaftPCBA EEPROM comprises one or more parameters, routines, and/or programsspecific to the interchangeable shaft assembly 200 and/or the shaftPCBA. The shaft PCBA may be coupled to the interchangeable shaftassembly 200 and/or integral with the surgical instrument 10. In someexamples, the shaft segment comprises a second shaft EEPROM. The secondshaft EEPROM comprises a plurality of algorithms, routines, parameters,and/or other data corresponding to one or more shaft assemblies 200and/or end effectors 300 that may be interfaced with the poweredsurgical instrument 10.

The position encoder segment (Segment 6) comprises one or more magneticangle rotary position encoders. The one or more magnetic angle rotaryposition encoders are configured to identify the rotational position ofthe motor 714, an interchangeable shaft assembly 200 (FIGS. 1 and 3),and/or an end effector 300 of the surgical instrument 10 (FIGS. 1-4). Insome examples, the magnetic angle rotary position encoders may becoupled to the safety controller and/or the main controller 717.

The motor circuit segment (Segment 7) comprises a motor 714 configuredto control movements of the powered surgical instrument 10 (FIGS. 1-4).The motor 714 is coupled to the main microcontroller processor 717 by anH-bridge driver comprising one or more H-bridge field-effect transistors(FETs) and a motor controller. The H-bridge driver is also coupled tothe safety controller. A motor current sensor is coupled in series withthe motor to measure the current draw of the motor. The motor currentsensor is in signal communication with the main controller 717 and/orthe safety controller. In some examples, the motor 714 is coupled to amotor electromagnetic interference (EMI) filter.

The motor controller controls a first motor flag and a second motor flagto indicate the status and position of the motor 714 to the maincontroller 717. The main controller 717 provides a pulse-widthmodulation (PWM) high signal, a PWM low signal, a direction signal, asynchronize signal, and a motor reset signal to the motor controllerthrough a buffer. The power segment is configured to provide a segmentvoltage to each of the circuit segments.

The power segment (Segment 8) comprises a battery coupled to the safetycontroller, the main controller 717, and additional circuit segments.The battery is coupled to the segmented circuit by a battery connectorand a current sensor. The current sensor is configured to measure thetotal current draw of the segmented circuit. In some examples, one ormore voltage converters are configured to provide predetermined voltagevalues to one or more circuit segments. For example, in some examples,the segmented circuit may comprise 3.3V voltage converters and/or 5Vvoltage converters. A boost converter is configured to provide a boostvoltage up to a predetermined amount, such as, for example, up to 13V.The boost converter is configured to provide additional voltage and/orcurrent during power intensive operations and prevent brownout orlow-power conditions.

A plurality of switches are coupled to the safety controller and/or themain controller 717. The switches may be configured to controloperations of the surgical instrument 10 (FIGS. 1-4), of the segmentedcircuit, and/or indicate a status of the surgical instrument 10. Abail-out door switch and Hall effect switch for bailout are configuredto indicate the status of a bail-out door. A plurality of articulationswitches, such as, for example, a left side articulation left switch, aleft side articulation right switch, a left side articulation centerswitch, a right side articulation left switch, a right side articulationright switch, and a right side articulation center switch are configuredto control articulation of an interchangeable shaft assembly 200 (FIGS.1 and 3) and/or the end effector 300 (FIGS. 1 and 4). A left sidereverse switch and a right side reverse switch are coupled to the maincontroller 717. The left side switches comprising the left sidearticulation left switch, the left side articulation right switch, theleft side articulation center switch, and the left side reverse switchare coupled to the main controller 717 by a left flex connector. Theright side switches comprising the right side articulation left switch,the right side articulation right switch, the right side articulationcenter switch, and the right side reverse switch are coupled to the maincontroller 717 by a right flex connector. A firing switch, a clamprelease switch, and a shaft engaged switch are coupled to the maincontroller 717.

Any suitable mechanical, electromechanical, or solid state switches maybe employed to implement the plurality of switches, in any combination.For example, the switches may be limit switches operated by the motionof components associated with the surgical instrument 10 (FIGS. 1-4) orthe presence of an object. Such switches may be employed to controlvarious functions associated with the surgical instrument 10. A limitswitch is an electromechanical device that consists of an actuatormechanically linked to a set of contacts. When an object comes intocontact with the actuator, the device operates the contacts to make orbreak an electrical connection. Limit switches are used in a variety ofapplications and environments because of their ruggedness, ease ofinstallation, and reliability of operation. They can determine thepresence or absence, passing, positioning, and end of travel of anobject. In other implementations, the switches may be solid stateswitches that operate under the influence of a magnetic field such asHall-effect devices, magneto-resistive (MR) devices, giantmagneto-resistive (GMR) devices, magnetometers, among others. In otherimplementations, the switches may be solid state switches that operateunder the influence of light, such as optical sensors, infrared sensors,ultraviolet sensors, among others. Still, the switches may be solidstate devices such as transistors (e.g., FET, Junction-FET, metal-oxidesemiconductor-FET (MOSFET), bipolar, and the like). Other switches mayinclude wireless switches, ultrasonic switches, accelerometers, inertialsensors, among others.

FIG. 6 is another block diagram of the control circuit 700 of thesurgical instrument of FIG. 1 illustrating interfaces between the handleassembly 702 and the power assembly 706 and between the handle assembly702 and the interchangeable shaft assembly 704 according to one aspectof this disclosure. The handle assembly 702 may comprise a maincontroller 717, a shaft assembly connector 726 and a power assemblyconnector 730. The power assembly 706 may include a power assemblyconnector 732, a power management circuit 734 that may comprise thepower management controller 716, a power modulator 738, and a currentsense circuit 736. The shaft assembly connectors 730, 732 form aninterface 727. The power management circuit 734 can be configured tomodulate power output of the battery 707 based on the power requirementsof the interchangeable shaft assembly 704 while the interchangeableshaft assembly 704 and the power assembly 706 are coupled to the handleassembly 702. The power management controller 716 can be programmed tocontrol the power modulator 738 of the power output of the powerassembly 706 and the current sense circuit 736 can be employed tomonitor power output of the power assembly 706 to provide feedback tothe power management controller 716 about the power output of thebattery 707 so that the power management controller 716 may adjust thepower output of the power assembly 706 to maintain a desired output. Theshaft assembly 704 comprises a shaft processor 719 coupled to anon-volatile memory 721 and shaft assembly connector 728 to electricallycouple the shaft assembly 704 to the handle assembly 702. The shaftassembly connectors 726, 728 form interface 725. The main controller717, the shaft processor 719, and/or the power management controller 716can be configured to implement one or more of the processes describedherein.

The surgical instrument 10 (FIGS. 1-4) may comprise an output device 742to a sensory feedback to a user. Such devices may comprise visualfeedback devices (e.g., an LCD display screen, LED indicators), audiofeedback devices (e.g., a speaker, a buzzer), or tactile feedbackdevices (e.g., haptic actuators). In certain circumstances, the outputdevice 742 may comprise a display 743 that may be included in the handleassembly 702. The shaft assembly controller 722 and/or the powermanagement controller 716 can provide feedback to a user of the surgicalinstrument 10 through the output device 742. The interface 727 can beconfigured to connect the shaft assembly controller 722 and/or the powermanagement controller 716 to the output device 742. The output device742 can be integrated with the power assembly 706. Communication betweenthe output device 742 and the shaft assembly controller 722 may beaccomplished through the interface 725 while the interchangeable shaftassembly 704 is coupled to the handle assembly 702. Having described acontrol circuit 700 (FIGS. 5A-5B and 6) for controlling the operation ofthe surgical instrument 10 (FIGS. 1-4), the disclosure now turns tovarious configurations of the surgical instrument 10 (FIGS. 1-4) andcontrol circuit 700.

FIG. 7 illustrates a control circuit 800 configured to control aspectsof the surgical instrument 10 (FIGS. 1-4) according to one aspect ofthis disclosure. The control circuit 800 can be configured to implementvarious processes described herein. The control circuit 800 may comprisea controller comprising one or more processors 802 (e.g.,microprocessor, microcontroller) coupled to at least one memory circuit804. The memory circuit 804 stores machine executable instructions thatwhen executed by the processor 802, cause the processor 802 to executemachine instructions to implement various processes described herein.The processor 802 may be any one of a number of single or multi-coreprocessors known in the art. The memory circuit 804 may comprisevolatile and non-volatile storage media. The processor 802 may includean instruction processing unit 806 and an arithmetic unit 808. Theinstruction processing unit may be configured to receive instructionsfrom the memory circuit 804.

FIG. 8 illustrates a combinational logic circuit 810 configured tocontrol aspects of the surgical instrument 10 (FIGS. 1-4) according toone aspect of this disclosure. The combinational logic circuit 810 canbe configured to implement various processes described herein. Thecircuit 810 may comprise a finite state machine comprising acombinational logic circuit 812 configured to receive data associatedwith the surgical instrument 10 at an input 814, process the data by thecombinational logic 812, and provide an output 816.

FIG. 9 illustrates a sequential logic circuit 820 configured to controlaspects of the surgical instrument 10 (FIGS. 1-4) according to oneaspect of this disclosure. The sequential logic circuit 820 or thecombinational logic circuit 822 can be configured to implement variousprocesses described herein. The circuit 820 may comprise a finite statemachine. The sequential logic circuit 820 may comprise a combinationallogic circuit 822, at least one memory circuit 824, and a clock 829, forexample. The at least one memory circuit 820 can store a current stateof the finite state machine. In certain instances, the sequential logiccircuit 820 may be synchronous or asynchronous. The combinational logiccircuit 822 is configured to receive data associated with the surgicalinstrument 10 an input 826, process the data by the combinational logiccircuit 822, and provide an output 828. In other aspects, the circuitmay comprise a combination of the processor 802 and the finite statemachine to implement various processes herein. In other aspects, thefinite state machine may comprise a combination of the combinationallogic circuit 810 and the sequential logic circuit 820.

Aspects may be implemented as an article of manufacture. The article ofmanufacture may include a computer readable storage medium arranged tostore logic, instructions, and/or data for performing various operationsof one or more aspects. For example, the article of manufacture maycomprise a magnetic disk, optical disk, flash memory, or firmwarecontaining computer program instructions suitable for execution by ageneral purpose processor or application specific processor.

FIG. 10 is a diagram of an absolute positioning system 1100 of thesurgical instrument 10 (FIGS. 1-4) where the absolute positioning system1100 comprises a controlled motor drive circuit arrangement comprising asensor arrangement 1102 according to one aspect of this disclosure. Thesensor arrangement 1102 for an absolute positioning system 1100 providesa unique position signal corresponding to the location of a displacementmember 1111. Turning briefly to FIGS. 2-4, in one aspect thedisplacement member 1111 represents the longitudinally movable drivemember 120 (FIG. 2) comprising a rack of drive teeth 122 for meshingengagement with a corresponding drive gear 86 of the gear reducerassembly 84. In other aspects, the displacement member 1111 representsthe firing member 220 (FIG. 3), which could be adapted and configured toinclude a rack of drive teeth. In yet another aspect, the displacementmember 1111 represents the firing bar 172 (FIG. 4) or the I-beam 178(FIG. 4), each of which can be adapted and configured to include a rackof drive teeth. Accordingly, as used herein, the term displacementmember is used generically to refer to any movable member of thesurgical instrument 10 such as the drive member 120, the firing member220, the firing bar 172, the I-beam 178, or any element that can bedisplaced. In one aspect, the longitudinally movable drive member 120 iscoupled to the firing member 220, the firing bar 172, and the I-beam178. Accordingly, the absolute positioning system 1100 can, in effect,track the displacement of the I-beam 178 by tracking the displacement ofthe longitudinally movable drive member 120. In various other aspects,the displacement member 1111 may be coupled to any sensor suitable formeasuring displacement. Thus, the longitudinally movable drive member120, the firing member 220, the firing bar 172, or the I-beam 178, orcombinations, may be coupled to any suitable displacement sensor.Displacement sensors may include contact or non-contact displacementsensors. Displacement sensors may comprise linear variable differentialtransformers (LVDT), differential variable reluctance transducers(DVRT), a slide potentiometer, a magnetic sensing system comprising amovable magnet and a series of linearly arranged Hall effect sensors, amagnetic sensing system comprising a fixed magnet and a series ofmovable linearly arranged Hall effect sensors, an optical sensing systemcomprising a movable light source and a series of linearly arrangedphoto diodes or photo detectors, or an optical sensing system comprisinga fixed light source and a series of movable linearly arranged photodiodes or photo detectors, or any combination thereof.

An electric motor 1120 can include a rotatable shaft 1116 that operablyinterfaces with a gear assembly 1114 that is mounted in meshingengagement with a set, or rack, of drive teeth on the displacementmember 1111. A sensor element 1126 may be operably coupled to a gearassembly 1114 such that a single revolution of the sensor element 1126corresponds to some linear longitudinal translation of the displacementmember 1111. An arrangement of gearing and sensors 1118 can be connectedto the linear actuator via a rack and pinion arrangement or a rotaryactuator via a spur gear or other connection. A power source 1129supplies power to the absolute positioning system 1100 and an outputindicator 1128 may display the output of the absolute positioning system1100. In FIG. 2, the displacement member 1111 represents thelongitudinally movable drive member 120 comprising a rack of drive teeth122 formed thereon for meshing engagement with a corresponding drivegear 86 of the gear reducer assembly 84. The displacement member 1111represents the longitudinally movable firing member 220, firing bar 172,I-beam 178, or combinations thereof.

A single revolution of the sensor element 1126 associated with theposition sensor 1112 is equivalent to a longitudinal displacement d1 ofthe of the displacement member 1111, where d1 is the longitudinaldistance that the displacement member 1111 moves from point “a” to point“b” after a single revolution of the sensor element 1126 coupled to thedisplacement member 1111. The sensor arrangement 1102 may be connectedvia a gear reduction that results in the position sensor 1112 completingone or more revolutions for the full stroke of the displacement member1111. The position sensor 1112 may complete multiple revolutions for thefull stroke of the displacement member 1111.

A series of switches 1122 a-1122 n, where n is an integer greater thanone, may be employed alone or in combination with gear reduction toprovide a unique position signal for more than one revolution of theposition sensor 1112. The state of the switches 1122 a-1122 n are fedback to a controller 1104 that applies logic to determine a uniqueposition signal corresponding to the longitudinal displacement d1+d2+ .. . dn of the displacement member 1111. The output 1124 of the positionsensor 1112 is provided to the controller 1104. The position sensor 1112of the sensor arrangement 1102 may comprise a magnetic sensor, an analogrotary sensor like a potentiometer, an array of analog Hall-effectelements, which output a unique combination of position signals orvalues.

The absolute positioning system 1100 provides an absolute position ofthe displacement member 1111 upon power up of the instrument withoutretracting or advancing the displacement member 1111 to a reset (zero orhome) position as may be required with conventional rotary encoders thatmerely count the number of steps forwards or backwards that the motor1120 has taken to infer the position of a device actuator, drive bar,knife, and the like.

The controller 1104 may be programmed to perform various functions suchas precise control over the speed and position of the knife andarticulation systems. In one aspect, the controller 1104 includes aprocessor 1108 and a memory 1106. The electric motor 1120 may be abrushed DC motor with a gearbox and mechanical links to an articulationor knife system. In one aspect, a motor driver 1110 may be an A3941available from Allegro Microsystems, Inc. Other motor drivers may bereadily substituted for use in the absolute positioning system 1100. Amore detailed description of the absolute positioning system 1100 isdescribed in U.S. patent application Ser. No. 15/130,590, entitledSYSTEMS AND METHODS FOR CONTROLLING A SURGICAL STAPLING AND CUTTINGINSTRUMENT, filed on Apr. 15, 2016, the entire disclosure of which isherein incorporated by reference.

The controller 1104 may be programmed to provide precise control overthe speed and position of the displacement member 1111 and articulationsystems. The controller 1104 may be configured to compute a response inthe software of the controller 1104. The computed response is comparedto a measured response of the actual system to obtain an “observed”response, which is used for actual feedback decisions. The observedresponse is a favorable, tuned, value that balances the smooth,continuous nature of the simulated response with the measured response,which can detect outside influences on the system.

The absolute positioning system 1100 may comprise and/or be programmedto implement a feedback controller, such as a PID, state feedback, andadaptive controller. A power source 1129 converts the signal from thefeedback controller into a physical input to the system, in this casevoltage. Other examples include pulse width modulation (PWM) of thevoltage, current, and force. Other sensor(s) 1118 may be provided tomeasure physical parameters of the physical system in addition toposition measured by the position sensor 1112. In a digital signalprocessing system, absolute positioning system 1100 is coupled to adigital data acquisition system where the output of the absolutepositioning system 1100 will have finite resolution and samplingfrequency. The absolute positioning system 1100 may comprise a compareand combine circuit to combine a computed response with a measuredresponse using algorithms such as weighted average and theoreticalcontrol loop that drives the computed response towards the measuredresponse. The computed response of the physical system takes intoaccount properties like mass, inertial, viscous friction, inductanceresistance, etc., to predict what the states and outputs of the physicalsystem will be by knowing the input. The controller 1104 may be acontrol circuit 700 (FIGS. 5A-5B).

The motor driver 1110 may be an A3941 available from AllegroMicrosystems, Inc. The A3941 driver 1110 is a full-bridge controller foruse with external N-channel power metal oxide semiconductor field effecttransistors (MOSFETs) specifically designed for inductive loads, such asbrush DC motors. The driver 1110 comprises a unique charge pumpregulator provides full (>10 V) gate drive for battery voltages down to7 V and allows the A3941 to operate with a reduced gate drive, down to5.5 V. A bootstrap capacitor may be employed to provide theabove-battery supply voltage required for N-channel MOSFETs. An internalcharge pump for the high-side drive allows DC (100% duty cycle)operation. The full bridge can be driven in fast or slow decay modesusing diode or synchronous rectification. In the slow decay mode,current recirculation can be through the high-side or the lowside FETs.The power FETs are protected from shoot-through by resistor adjustabledead time. Integrated diagnostics provide indication of undervoltage,overtemperature, and power bridge faults, and can be configured toprotect the power MOSFETs under most short circuit conditions. Othermotor drivers may be readily substituted for use in the absolutepositioning system 1100.

Having described a general architecture for implementing aspects of anabsolute positioning system 1100 for a sensor arrangement 1102, thedisclosure now turns to FIGS. 11 and 12 for a description of one aspectof a sensor arrangement 1102 for the absolute positioning system 1100.FIG. 11 is an exploded perspective view of the sensor arrangement 1102for the absolute positioning system 1100 showing a circuit 1205 and therelative alignment of the elements of the sensor arrangement 1102,according to one aspect. The sensor arrangement 1102 for an absolutepositioning system 1100 comprises a position sensor 1200, a magnet 1202sensor element, a magnet holder 1204 that turns once every full strokeof the displacement member 1111, and a gear assembly 1206 to provide agear reduction. With reference briefly to FIG. 2, the displacementmember 1111 may represent the longitudinally movable drive member 120comprising a rack of drive teeth 122 for meshing engagement with acorresponding drive gear 86 of the gear reducer assembly 84. Returningto FIG. 11, a structural element such as bracket 1216 is provided tosupport the gear assembly 1206, the magnet holder 1204, and the magnet1202. The position sensor 1200 comprises magnetic sensing elements suchas Hall elements and is placed in proximity to the magnet 1202. As themagnet 1202 rotates, the magnetic sensing elements of the positionsensor 1200 determine the absolute angular position of the magnet 1202over one revolution.

The sensor arrangement 1102 may comprises any number of magnetic sensingelements, such as, for example, magnetic sensors classified according towhether they measure the total magnetic field or the vector componentsof the magnetic field. The techniques used to produce both types ofmagnetic sensors encompass many aspects of physics and electronics. Thetechnologies used for magnetic field sensing include search coil,fluxgate, optically pumped, nuclear precession, SQUID, Hall-effect,anisotropic magnetoresistance, giant magnetoresistance, magnetic tunneljunctions, giant magnetoimpedance, magnetostrictive/piezoelectriccomposites, magnetodiode, magnetotransistor, fiber optic, magnetooptic,and microelectromechanical systems-based magnetic sensors, among others.

A gear assembly comprises a first gear 1208 and a second gear 1210 inmeshing engagement to provide a 3:1 gear ratio connection. A third gear1212 rotates about a shaft 1214. The third gear 1212 is in meshingengagement with the displacement member 1111 (or 120 as shown in FIG. 2)and rotates in a first direction as the displacement member 1111advances in a distal direction D and rotates in a second direction asthe displacement member 1111 retracts in a proximal direction P. Thesecond gear 1210 also rotates about the shaft 1214 and, therefore,rotation of the second gear 1210 about the shaft 1214 corresponds to thelongitudinal translation of the displacement member 1111. Thus, one fullstroke of the displacement member 1111 in either the distal or proximaldirections D, P corresponds to three rotations of the second gear 1210and a single rotation of the first gear 1208. Since the magnet holder1204 is coupled to the first gear 1208, the magnet holder 1204 makes onefull rotation with each full stroke of the displacement member 1111.

The position sensor 1200 is supported by a position sensor holder 1218defining an aperture 1220 suitable to contain the position sensor 1200in precise alignment with a magnet 1202 rotating below within the magnetholder 1204. The fixture is coupled to the bracket 1216 and to thecircuit 1205 and remains stationary while the magnet 1202 rotates withthe magnet holder 1204. A hub 1222 is provided to mate with the firstgear 1208 and the magnet holder 1204. The second gear 1210 and thirdgear 1212 coupled to shaft 1214 also are shown.

FIG. 12 is a diagram of a position sensor 1200 for an absolutepositioning system 1100 comprising a magnetic rotary absolutepositioning system according to one aspect of this disclosure. Theposition sensor 1200 may be implemented as an AS5055EQFT single-chipmagnetic rotary position sensor available from Austria Microsystems, AG.The position sensor 1200 is interfaced with the controller 1104 toprovide an absolute positioning system 1100. The position sensor 1200 isa low-voltage and low-power component and includes four Hall-effectelements 1228A, 1228B, 1228C, 1228D in an area 1230 of the positionsensor 1200 that is located above the magnet 1202 (FIGS. 15 and 16). Ahigh-resolution ADC 1232 and a smart power management controller 1238are also provided on the chip. A CORDIC processor 1236 (for CoordinateRotation Digital Computer), also known as the digit-by-digit method andVolder's algorithm, is provided to implement a simple and efficientalgorithm to calculate hyperbolic and trigonometric functions thatrequire only addition, subtraction, bitshift, and table lookupoperations. The angle position, alarm bits, and magnetic fieldinformation are transmitted over a standard serial communicationinterface such as an SPI interface 1234 to the controller 1104. Theposition sensor 1200 provides 12 or 14 bits of resolution. The positionsensor 1200 may be an AS5055 chip provided in a small QFN 16-pin4×4×0.85 mm package.

The Hall-effect elements 1228A, 1228B, 1228C, 1228D are located directlyabove the rotating magnet 1202 (FIG. 11). The Hall-effect is awell-known effect and for expediency will not be described in detailherein, however, generally, the Hall-effect produces a voltagedifference (the Hall voltage) across an electrical conductor transverseto an electric current in the conductor and a magnetic fieldperpendicular to the current. A Hall coefficient is defined as the ratioof the induced electric field to the product of the current density andthe applied magnetic field. It is a characteristic of the material fromwhich the conductor is made, since its value depends on the type,number, and properties of the charge carriers that constitute thecurrent. In the AS5055 position sensor 1200, the Hall-effect elements1228A, 1228B, 1228C, 1228D are capable producing a voltage signal thatis indicative of the absolute position of the magnet 1202 in terms ofthe angle over a single revolution of the magnet 1202. This value of theangle, which is unique position signal, is calculated by the CORDICprocessor 1236 is stored onboard the AS5055 position sensor 1200 in aregister or memory. The value of the angle that is indicative of theposition of the magnet 1202 over one revolution is provided to thecontroller 1104 in a variety of techniques, e.g., upon power up or uponrequest by the controller 1104.

The AS5055 position sensor 1200 requires only a few external componentsto operate when connected to the controller 1104. Six wires are neededfor a simple application using a single power supply: two wires forpower and four wires 1240 for the SPI interface 1234 with the controller1104. A seventh connection can be added in order to send an interrupt tothe controller 1104 to inform that a new valid angle can be read. Uponpower-up, the AS5055 position sensor 1200 performs a full power-upsequence including one angle measurement. The completion of this cycleis indicated as an INT output 1242, and the angle value is stored in aninternal register. Once this output is set, the AS5055 position sensor1200 suspends to sleep mode. The controller 1104 can respond to the INTrequest at the INT output 1242 by reading the angle value from theAS5055 position sensor 1200 over the SPI interface 1234. Once the anglevalue is read by the controller 1104, the INT output 1242 is clearedagain. Sending a “read angle” command by the SPI interface 1234 by thecontroller 1104 to the position sensor 1200 also automatically powers upthe chip and starts another angle measurement. As soon as the controller1104 has completed reading of the angle value, the INT output 1242 iscleared and a new result is stored in the angle register. The completionof the angle measurement is again indicated by setting the INT output1242 and a corresponding flag in the status register.

Due to the measurement principle of the AS5055 position sensor 1200,only a single angle measurement is performed in very short time (˜600μs) after each power-up sequence. As soon as the measurement of oneangle is completed, the AS5055 position sensor 1200 suspends topower-down state. An on-chip filtering of the angle value by digitalaveraging is not implemented, as this would require more than one anglemeasurement and, consequently, a longer power-up time that is notdesired in low-power applications. The angle jitter can be reduced byaveraging of several angle samples in the controller 1104. For example,an averaging of four samples reduces the jitter by 6 dB (50%).

FIG. 13 is a section view of an end effector 2502 of the surgicalinstrument 10 (FIGS. 1-4) showing an I-beam 2514 firing stroke relativeto tissue 2526 grasped within the end effector 2502 according to oneaspect of this disclosure. The end effector 2502 is configured tooperate with the surgical instrument 10 shown in FIGS. 1-4. The endeffector 2502 comprises an anvil 2516 and an elongated channel 2503 witha staple cartridge 2518 positioned in the elongated channel 2503. Afiring bar 2520 is translatable distally and proximally along alongitudinal axis 2515 of the end effector 2502. When the end effector2502 is not articulated, the end effector 2502 is in line with the shaftof the instrument. An I-beam 2514 comprising a cutting edge 2509 isillustrated at a distal portion of the firing bar 2520. A wedge sled2513 is positioned in the staple cartridge 2518. As the I-beam 2514translates distally, the cutting edge 2509 contacts and may cut tissue2526 positioned between the anvil 2516 and the staple cartridge 2518.Also, the I-beam 2514 contacts the wedge sled 2513 and pushes itdistally, causing the wedge sled 2513 to contact staple drivers 2511.The staple drivers 2511 may be driven up into staples 2505, causing thestaples 2505 to advance through tissue and into pockets 2507 defined inthe anvil 2516, which shape the staples 2505.

An example I-beam 2514 firing stroke is illustrated by a chart 2529aligned with the end effector 2502. Example tissue 2526 is also shownaligned with the end effector 2502. The firing member stroke maycomprise a stroke begin position 2527 and a stroke end position 2528.During an I-beam 2514 firing stroke, the I-beam 2514 may be advanceddistally from the stroke begin position 2527 to the stroke end position2528. The I-beam 2514 is shown at one example location of a stroke beginposition 2527. The I-beam 2514 firing member stroke chart 2529illustrates five firing member stroke regions 2517, 2519, 2521, 2523,2525. In a first firing stroke region 2517, the I-beam 2514 may begin toadvance distally. In the first firing stroke region 2517, the I-beam2514 may contact the wedge sled 2513 and begin to move it distally.While in the first region, however, the cutting edge 2509 may notcontact tissue and the wedge sled 2513 may not contact a staple driver2511. After static friction is overcome, the force to drive the I-beam2514 in the first region 2517 may be substantially constant.

In the second firing member stroke region 2519, the cutting edge 2509may begin to contact and cut tissue 2526. Also, the wedge sled 2513 maybegin to contact staple drivers 2511 to drive staples 2505. Force todrive the I-beam 2514 may begin to ramp up. As shown, tissue encounteredinitially may be compressed and/or thinner because of the way that theanvil 2516 pivots relative to the staple cartridge 2518. In the thirdfiring member stroke region 2521, the cutting edge 2509 may continuouslycontact and cut tissue 2526 and the wedge sled 2513 may repeatedlycontact staple drivers 2511. Force to drive the I-beam 2514 may plateauin the third region 2521. By the fourth firing stroke region 2523, forceto drive the I-beam 2514 may begin to decline. For example, tissue inthe portion of the end effector 2502 corresponding to the fourth firingregion 2523 may be less compressed than tissue closer to the pivot pointof the anvil 2516, requiring less force to cut. Also, the cutting edge2509 and wedge sled 2513 may reach the end of the tissue 2526 while inthe fourth region 2523. When the I-beam 2514 reaches the fifth region2525, the tissue 2526 may be completely severed. The wedge sled 2513 maycontact one or more staple drivers 2511 at or near the end of thetissue. Force to advance the I-beam 2514 through the fifth region 2525may be reduced and, in some examples, may be similar to the force todrive the I-beam 2514 in the first region 2517. At the conclusion of thefiring member stroke, the I-beam 2514 may reach the stroke end position2528. The positioning of firing member stroke regions 2517, 2519, 2521,2523, 2525 in FIG. 13 is just one example. In some examples, differentregions may begin at different positions along the end effectorlongitudinal axis 2515, for example, based on the positioning of tissuebetween the anvil 2516 and the staple cartridge 2518.

As discussed above and with reference now to FIGS. 10-13, the electricmotor 1122 positioned within the handle assembly of the surgicalinstrument 10 (FIGS. 1-4) can be utilized to advance and/or retract thefiring system of the shaft assembly, including the I-beam 2514, relativeto the end effector 2502 of the shaft assembly in order to staple and/orincise tissue captured within the end effector 2502. The I-beam 2514 maybe advanced or retracted at a desired speed, or within a range ofdesired speeds. The controller 1104 may be configured to control thespeed of the I-beam 2514. The controller 1104 may be configured topredict the speed of the I-beam 2514 based on various parameters of thepower supplied to the electric motor 1122, such as voltage and/orcurrent, for example, and/or other operating parameters of the electricmotor 1122 or external influences. The controller 1104 may be configuredto predict the current speed of the I-beam 2514 based on the previousvalues of the current and/or voltage supplied to the electric motor1122, and/or previous states of the system like velocity, acceleration,and/or position. The controller 1104 may be configured to sense thespeed of the I-beam 2514 utilizing the absolute positioning sensorsystem described herein. The controller can be configured to compare thepredicted speed of the I-beam 2514 and the sensed speed of the I-beam2514 to determine whether the power to the electric motor 1122 should beincreased in order to increase the speed of the I-beam 2514 and/ordecreased in order to decrease the speed of the I-beam 2514. U.S. Pat.No. 8,210,411, entitled MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT, whichis incorporated herein by reference in its entirety. U.S. Pat. No.7,845,537, entitled SURGICAL INSTRUMENT HAVING RECORDING CAPABILITIES,which is incorporated herein by reference in its entirety.

Force acting on the I-beam 2514 may be determined using varioustechniques. The I-beam 2514 force may be determined by measuring themotor 2504 current, where the motor 2504 current is based on the loadexperienced by the I-beam 2514 as it advances distally. The I-beam 2514force may be determined by positioning a strain gauge on the drivemember 120 (FIG. 2), the firing member 220 (FIG. 2), I-beam 2514 (I-beam178, FIG. 20), the firing bar 172 (FIG. 2), and/or on a proximal end ofthe cutting edge 2509. The I-beam 2514 force may be determined bymonitoring the actual position of the I-beam 2514 moving at an expectedvelocity based on the current set velocity of the motor 2504 after apredetermined elapsed period T₁ and comparing the actual position of theI-beam 2514 relative to the expected position of the I-beam 2514 basedon the current set velocity of the motor 2504 at the end of the periodT₁. Thus, if the actual position of the I-beam 2514 is less than theexpected position of the I-beam 2514, the force on the I-beam 2514 isgreater than a nominal force. Conversely, if the actual position of theI-beam 2514 is greater than the expected position of the I-beam 2514,the force on the I-beam 2514 is less than the nominal force. Thedifference between the actual and expected positions of the I-beam 2514is proportional to the deviation of the force on the I-beam 2514 fromthe nominal force. Such techniques are described in U.S. patentapplication Ser. No. 15/628,075, titled SYSTEMS AND METHODS FORCONTROLLING MOTOR VELOCITY OF A SURGICAL STAPLING AND CUTTINGINSTRUMENT, filed Jun. 20, 2017, which is incorporated herein byreference in its entirety.

FIG. 14 illustrates a block diagram of a surgical instrument 2500programmed to control distal translation of a displacement memberaccording to one aspect of this disclosure. In one aspect, the surgicalinstrument 2500 is programmed to control distal translation of adisplacement member 1111 such as the I-beam 2514. The surgicalinstrument 2500 comprises an end effector 2502 that may comprise ananvil 2516, an I-beam 2514 (including a sharp cutting edge 2509), and aremovable staple cartridge 2518. The end effector 2502, anvil 2516,I-beam 2514, and staple cartridge 2518 may be configured as describedherein, for example, with respect to FIGS. 1-13.

The position, movement, displacement, and/or translation of a linerdisplacement member 1111, such as the I-beam 2514, can be measured bythe absolute positioning system 1100, sensor arrangement 1102, andposition sensor 1200 as shown in FIGS. 10-12 and represented as positionsensor 2534 in FIG. 14. Because the I-beam 2514 is coupled to thelongitudinally movable drive member 120, the position of the I-beam 2514can be determined by measuring the position of the longitudinallymovable drive member 120 employing the position sensor 2534.Accordingly, in the following description, the position, displacement,and/or translation of the I-beam 2514 can be achieved by the positionsensor 2534 as described herein. A control circuit 2510, such as thecontrol circuit 700 described in FIGS. 5A and 5B, may be programmed tocontrol the translation of the displacement member 1111, such as theI-beam 2514, as described in connection with FIGS. 10-12. The controlcircuit 2510, in some examples, may comprise one or moremicrocontrollers, microprocessors, or other suitable processors forexecuting instructions that cause the processor or processors to controlthe displacement member, e.g., the I-beam 2514, in the manner described.In one aspect, a timer/counter circuit 2531 provides an output signal,such as elapsed time or a digital count, to the control circuit 2510 tocorrelate the position of the I-beam 2514 as determined by the positionsensor 2534 with the output of the timer/counter circuit 2531 such thatthe control circuit 2510 can determine the position of the I-beam 2514at a specific time (t) relative to a starting position. Thetimer/counter circuit 2531 may be configured to measure elapsed time,count external evens, or time external events.

The control circuit 2510 may generate a motor set point signal 2522. Themotor set point signal 2522 may be provided to a motor controller 2508.The motor controller 2508 may comprise one or more circuits configuredto provide a motor drive signal 2524 to the motor 2504 to drive themotor 2504 as described herein. In some examples, the motor 2504 may bea brushed DC electric motor, such as the motor 82, 714, 1120 shown inFIGS. 1, 5B, 10. For example, the velocity of the motor 2504 may beproportional to the motor drive signal 2524. In some examples, the motor2504 may be a brushless direct current (DC) electric motor and the motordrive signal 2524 may comprise a pulse-width-modulated (PWM) signalprovided to one or more stator windings of the motor 2504. Also, in someexamples, the motor controller 2508 may be omitted and the controlcircuit 2510 may generate the motor drive signal 2524 directly.

The motor 2504 may receive power from an energy source 2512. The energysource 2512 may be or include a battery, a super capacitor, or any othersuitable energy source 2512. The motor 2504 may be mechanically coupledto the I-beam 2514 via a transmission 2506. The transmission 2506 mayinclude one or more gears or other linkage components to couple themotor 2504 to the I-beam 2514. A position sensor 2534 may sense aposition of the I-beam 2514. The position sensor 2534 may be or includeany type of sensor that is capable of generating position data thatindicates a position of the I-beam 2514. In some examples, the positionsensor 2534 may include an encoder configured to provide a series ofpulses to the control circuit 2510 as the I-beam 2514 translatesdistally and proximally. The control circuit 2510 may track the pulsesto determine the position of the I-beam 2514. Other suitable positionsensor may be used, including, for example, a proximity sensor. Othertypes of position sensors may provide other signals indicating motion ofthe I-beam 2514. Also, in some examples, the position sensor 2534 may beomitted. Where the motor 2504 is a stepper motor, the control circuit2510 may track the position of the I-beam 2514 by aggregating the numberand direction of steps that the motor 2504 has been instructed toexecute. The position sensor 2534 may be located in the end effector2502 or at any other portion of the instrument.

The control circuit 2510 may be in communication with one or moresensors 2538. The sensors 2538 may be positioned on the end effector2502 and adapted to operate with the surgical instrument 2500 to measurethe various derived parameters such as gap distance versus time, tissuecompression versus time, and anvil strain versus time. The sensors 2538may comprise a magnetic sensor, a magnetic field sensor, a strain gauge,a pressure sensor, a force sensor, an inductive sensor such as an eddycurrent sensor, a resistive sensor, a capacitive sensor, an opticalsensor, and/or any other suitable sensor for measuring one or moreparameters of the end effector 2502. The sensors 2538 may include one ormore sensors.

The one or more sensors 2538 may comprise a strain gauge, such as amicro-strain gauge, configured to measure the magnitude of the strain inthe anvil 2516 during a clamped condition. The strain gauge provides anelectrical signal whose amplitude varies with the magnitude of thestrain. The sensors 2538 may comprise a pressure sensor configured todetect a pressure generated by the presence of compressed tissue betweenthe anvil 2516 and the staple cartridge 2518. The sensors 2538 may beconfigured to detect impedance of a tissue section located between theanvil 2516 and the staple cartridge 2518 that is indicative of thethickness and/or fullness of tissue located therebetween.

The sensors 2538 may be is configured to measure forces exerted on theanvil 2516 by the closure drive system 30. For example, one or moresensors 2538 can be at an interaction point between the closure tube 260(FIG. 3) and the anvil 2516 to detect the closure forces applied by theclosure tube 260 to the anvil 2516. The forces exerted on the anvil 2516can be representative of the tissue compression experienced by thetissue section captured between the anvil 2516 and the staple cartridge2518. The one or more sensors 2538 can be positioned at variousinteraction points along the closure drive system 30 (FIG. 2) to detectthe closure forces applied to the anvil 2516 by the closure drive system30. The one or more sensors 2538 may be sampled in real time during aclamping operation by a processor as described in FIGS. 5A-5B. Thecontrol circuit 2510 receives real-time sample measurements to provideanalyze time based information and assess, in real time, closure forcesapplied to the anvil 2516.

A current sensor 2536 can be employed to measure the current drawn bythe motor 2504. The force required to advance the I-beam 2514corresponds to the current drawn by the motor 2504. The force isconverted to a digital signal and provided to the control circuit 2510.

Using the physical properties of the instruments disclosed herein inconnection with FIGS. 1-14, and with reference to FIG. 14, the controlcircuit 2510 can be configured to simulate the response of the actualsystem of the instrument in the software of the controller. Adisplacement member can be actuated to move an I-beam 2514 in the endeffector 2502 at or near a target velocity. The surgical instrument 2500can include a feedback controller, which can be one of any feedbackcontrollers, including, but not limited to a PID, a State Feedback, LQR,and/or an Adaptive controller, for example. The surgical instrument 2500can include a power source to convert the signal from the feedbackcontroller into a physical input such as case voltage, pulse widthmodulated (PWM) voltage, frequency modulated voltage, current, torque,and/or force, for example.

The actual drive system of the surgical instrument 2500 is configured todrive the displacement member, cutting member, or I-beam 2514, by abrushed DC motor with gearbox and mechanical links to an articulationand/or knife system. Another example is the electric motor 2504 thatoperates the displacement member and the articulation driver, forexample, of an interchangeable shaft assembly. An outside influence isan unmeasured, unpredictable influence of things like tissue,surrounding bodies and friction on the physical system. Such outsideinfluence can be referred to as drag which acts in opposition to theelectric motor 2504. The outside influence, such as drag, may cause theoperation of the physical system to deviate from a desired operation ofthe physical system.

Before explaining aspects of the surgical instrument 2500 in detail, itshould be noted that the example aspects are not limited in applicationor use to the details of construction and arrangement of partsillustrated in the accompanying drawings and description. The exampleaspects may be implemented or incorporated in other aspects, variationsand modifications, and may be practiced or carried out in various ways.Further, unless otherwise indicated, the terms and expressions employedherein have been chosen for the purpose of describing the exampleaspects for the convenience of the reader and are not for the purpose oflimitation thereof. Also, it will be appreciated that one or more of thefollowing-described aspects, expressions of aspects and/or examples, canbe combined with any one or more of the other following-describedaspects, expressions of aspects and/or examples.

Various example aspects are directed to a surgical instrument 2500comprising an end effector 2502 with motor-driven surgical stapling andcutting implements. For example, a motor 2504 may drive a displacementmember distally and proximally along a longitudinal axis of the endeffector 2502. The end effector 2502 may comprise a pivotable anvil 2516and, when configured for use, a staple cartridge 2518 positionedopposite the anvil 2516. A clinician may grasp tissue between the anvil2516 and the staple cartridge 2518, as described herein. When ready touse the instrument 2500, the clinician may provide a firing signal, forexample by depressing a trigger of the instrument 2500. In response tothe firing signal, the motor 2504 may drive the displacement memberdistally along the longitudinal axis of the end effector 2502 from aproximal stroke begin position to a stroke end position distal of thestroke begin position. As the displacement member translates distally,an I-beam 2514 with a cutting element positioned at a distal end, maycut the tissue between the staple cartridge 2518 and the anvil 2516.

In various examples, the surgical instrument 2500 may comprise a controlcircuit 2510 programmed to control the distal translation of thedisplacement member, such as the I-beam 2514, for example, based on oneor more tissue conditions. The control circuit 2510 may be programmed tosense tissue conditions, such as thickness, either directly orindirectly, as described herein. The control circuit 2510 may beprogrammed to select a firing control program based on tissueconditions. A firing control program may describe the distal motion ofthe displacement member. Different firing control programs may beselected to better treat different tissue conditions. For example, whenthicker tissue is present, the control circuit 2510 may be programmed totranslate the displacement member at a lower velocity and/or with lowerpower. When thinner tissue is present, the control circuit 2510 may beprogrammed to translate the displacement member at a higher velocityand/or with higher power.

In some examples, the control circuit 2510 may initially operate themotor 2504 in an open-loop configuration for a first open-loop portionof a stroke of the displacement member. Based on a response of theinstrument 2500 during the open-loop portion of the stroke, the controlcircuit 2510 may select a firing control program. The response of theinstrument may include, a translation distance of the displacementmember during the open-loop portion, a time elapsed during the open-loopportion, energy provided to the motor 2504 during the open-loop portion,a sum of pulse widths of a motor drive signal, etc. After the open-loopportion, the control circuit 2510 may implement the selected firingcontrol program for a second portion of the displacement member stroke.For example, during the closed loop portion of the stroke, the controlcircuit 2510 may modulate the motor 2504 based on translation datadescribing a position of the displacement member in a closed-loop mannerto translate the displacement member at a constant velocity.

FIG. 15 illustrates a diagram 2580 plotting two example displacementmember strokes executed according to one aspect of this disclosure. Thediagram 2580 comprises two axes. A horizontal axis 2584 indicateselapsed time. A vertical axis 2582 indicates the position of the I-beam2514 between a stroke begin position 2586 and a stroke end position2588. On the horizontal axis 2584, the control circuit 2510 may receivethe firing signal and begin providing the initial motor setting at t₀.The open-loop portion of the displacement member stroke is an initialtime period that may elapse between t₀ and t₁.

A first example 2592 shows a response of the surgical instrument 2500when thick tissue is positioned between the anvil 2516 and the staplecartridge 2518. During the open-loop portion of the displacement memberstroke, e.g., the initial time period between t₀ and t₁, the I-beam 2514may traverse from the stroke begin position 2586 to position 2594. Thecontrol circuit 2510 may determine that position 2594 corresponds to afiring control program that advances the I-beam 2514 at a selectedconstant velocity (Vslow), indicated by the slope of the example 2592after t₁ (e.g., in the closed loop portion). The control circuit 2510may drive I-beam 2514 to the velocity Vslow by monitoring the positionof I-beam 2514 and modulating the motor set point 2522 and/or motordrive signal 2524 to maintain Vslow. A second example 2590 shows aresponse of the surgical instrument 2500 when thin tissue is positionedbetween the anvil 2516 and the staple cartridge 2518.

During the initial time period (e.g., the open-loop period) between t₀and t₁, the I-beam 2514 may traverse from the stroke begin position 2586to position 2596. The control circuit may determine that position 2596corresponds to a firing control program that advances the displacementmember at a selected constant velocity (Vfast). Because the tissue inexample 2590 is thinner than the tissue in example 2592, it may provideless resistance to the motion of the I-beam 2514. As a result, theI-beam 2514 may traverse a larger portion of the stroke during theinitial time period. Also, in some examples, thinner tissue (e.g., alarger portion of the displacement member stroke traversed during theinitial time period) may correspond to higher displacement membervelocities after the initial time period.

Closed Loop Feedback Control of Motor Velocity of a Surgical Staplingand Cutting Instrument Based on Magnitude of Velocity Error Measurements

During use of a motorized surgical stapling and cutting instrument it ispossible that a velocity controlled system error may occur between thecommand velocity and the actual measured velocity of the cutting memberor firing member. Therefore, it may be desirable to provide a closedloop feedback system that adjusts the velocity of the cutting member orfiring member based on the magnitude of one or more error termsdetermined based on the difference between an actual speed and a commandspeed over a specified increment of time/distance.

FIGS. 16-22 illustrate various graphical representations and processesfor determining the error between a directed velocity of a displacementmember and the actual velocity of a displacement member and adjustingthe directed velocity of the displacement member based on the error. Inthe aspects illustrated in FIGS. 16-22 the displacement member is theI-beam 2514. In other aspects, however, the displacement member may bethe drive member 120 (FIG. 2), the firing member 220, 2509 (FIGS. 3,13), the firing bar 172 (FIG. 4), the I-beam 178, 2514 (FIGS. 4, 13, 14)or any combination thereof.

Turning now to FIG. 16, there is a shown a graph 8500 depicting velocity(v) of a displacement member as a function of displacement (δ) of thedisplacement member according to one aspect of this disclosure. In theillustrated aspect, the displacement (δ) of the I-beam 2514 is shownalong the horizontal axis 8502 and the velocity (v) of the I-beam 2514is shown along the vertical axis 8504. It will be appreciate that thevelocity of the motor 2504 may be shown along the vertical axis 8504instead of the velocity of the I-beam 2514. The function shown in dashedline represents directed velocity 8506 of the I-beam 2514 and thefunction shown in solid line form represents actual velocity 8508 of theI-beam 2514. The directed velocity 8506 is based on a motor set point2522 velocity applied to the motor control 2508 circuit by the controlcircuit 2510. In response, the motor control 2508 applies acorresponding motor drive signal 2524 having a predetermined duty cycleto the motor 2504 to set the velocity of the motor 2504 to achieve adirected velocity 8506 of the I-beam 2514, as shown in FIG. 14. Thedirected velocity 8506 also can be referred to as the command velocity.Based on the motor set point 2522 velocity, displacement of the I-beam2514 is given by the directed velocity 8506. However, due to outsideinfluences, the actual displacement of the I-beam 2514 is given by theactual velocity 8508. As can be ascertained from the graph 8500, adifference is evident between the directed velocity 8506 and the actualvelocity 8508 of the I-beam 2514. The differences between the directedvelocity 8506 and the actual velocity 8508 are referred to herein as thevelocity error terms such as short term error (S), cumulative error (C),rate of change error (R), and number of overshoots error (N). The shortterm error S represents how far the actual velocity 8508 is from thedirected velocity 8506 at a displacement of δ₁. The cumulative error C,shown as the cross-hatched area over time (mm²/sec), represents errordeviation between actual velocity 8508 and directed velocity 8506accumulated over time. The rate of change R, given by the slope b/a,represents the rate at which the actual velocity 8508 is approaching thedirected velocity 8506. Finally, the number of overshoots N representsthe number of times the actual velocity 8508 overshoots or undershootsthe directed velocity 8506.

FIG. 17 is a graph 8510 depicting velocity (v) of a displacement memberas a function of displacement (δ) of the displacement member accordingto one aspect of this disclosure. In the illustrated aspect, thedisplacement (δ) (mm) of the I-beam 2514 is shown along the horizontalaxis 8512 and the velocity (v) (mm/sec) of the I-beam 2514 is shownalong the vertical axis 8514. The horizontal axis 8512 is scaled torepresent the displacement of the I-beam 2514 over a length X of thestaple cartridge 2518, such as 10-60 mm staple cartridges, for example.In one aspect, for a 60 mm cartridge 2518 the I-beam 2514 displacementis 60 mm and the velocity of the I-beam 2514 varies from 0-30 mm/sec.The function shown in dashed line form represents directed velocity 8506of the I-beam 2514 and the function shown in solid line form representsactual velocity 8508 of the I-beam 2514. As shown by the graph 8510, theI-beam 2514 displacement along the staple cartridge 2518 stroke isdivided into three zones 8516, 8518, 8520. In the first zone 8516 (0 toδ₂ mm), at the beginning of the stroke (0 mm), the control circuit 2510sets the motor drive signal 2524 to a first duty cycle (DS1). In thesecond zone 8518 (δ₂ mm to δ₃ mm), the control circuit 2510 sets themotor drive signal 2524 to a second duty cycle (DS2). In the third zone8520 (δ₃ mm to end of stroke), the control circuit 2510 sets the motordrive signal 2524 to a third duty cycle (DS3). In accordance with thisaspect, the directed velocity 8506 is adjusted based on the position ofthe I-beam 2514 during a firing stroke. Although, the graph 8510 shows afiring stroke divided into three zones 8516, 8518, 8520, it will beappreciated that the firing stroke may be divided into additional orfewer zones. The surgical instrument 2500 comprises a closed loopfeedback system that adjusts or controls the duty cycle of the motordrive signal 2524 to adjust the velocity of the I-beam 2514 based on themagnitude of one or more of the error terms S, C, R, and N based on thedifference between the directed velocity 8506 and the actual velocity8508 over a specified increment of either time or distance as the I-beam2514 traverses the staple cartridge 2518. In one aspect, the controlsystem 2500 employs PID error control to control the velocity of themotor 2504 at discrete time/distance locations δ_(n) of the I-beam 2514stroke and employs the PID errors to control constant velocity of theI-beam 2514 between the discrete time/displacement checks.

Referring to the first zone 8516, at the beginning of the stroke, thecontrol circuit 2510 provides a motor set point 2522 to the motorcontrol 2508, which applies a motor drive signal 2524 having a firstduty cycle (DS1) to the motor 2504 to set the directed velocity 8506 ofthe I-beam 2514 to V₂. As the I-beam 2514 advances distally, theposition sensor 2534 and the timer/counter 2531 circuit track theposition and time, respectively, of the I-beam 2514 to determine theactual position and the actual velocity 8508 of the I-beam 2514. As theposition of the I-beam 2514 approaches δ₁, the actual velocity 8508begins a positive transition towards the directed velocity 8506. Asshown, the actual velocity 8508 lags the directed velocity 8506 by S1and has lagged the directed velocity 8506 by a cumulative error C1 overa period of time. At δ₁ the rate of change of the actual velocity 8508is R1. As the I-beam 2514 advances distally towards δ₂, the actualvelocity 8508 overshoots N1₁, N1₂ . . . N1_(n) the directed velocity8506 and eventually settles at the directed velocity 8506.

Turning now to the second zone 8518, at δ₂ the control circuit 2510provides a new motor set point 2522 to the motor control 2508, whichapplies a new motor drive signal 2524 having a second duty cycle (DS2)to the motor 2504 to decrease the directed velocity 8506 of the I-beam2514 to V₁. At δ₂ the actual velocity 8508 of the I-beam 2514 begins anegative transition to the lower directed velocity 8506. As the I-beam2514 advances distally, the actual velocity 8508 lags the directedvelocity 8506 by S2 and lags the directed velocity 8506 by a cumulativeerror C2 over a time period and the rate of change of the actualvelocity 8508 is R2. As the I-beam 2514 advances distally towards δ₃,the actual velocity 8508 undershoots N2₁, N2₂ . . . N2_(n) the directedvelocity 8506 and eventually settles at the directed velocity 8506.

Turning now to the third zone 8520, at δ₃ the control circuit 2510provides a new motor set point 2522 to the motor control 2508, whichapplies a new motor drive signal 2524 having a third duty cycle (DS3) tothe motor 2504 to increase the directed velocity 8506 of the I-beam 2514to V₃. At δ₃ the actual velocity 8508 of the I-beam 2514 begins apositive transition to the higher directed velocity 8506. As the I-beam2514 advances distally, the actual velocity 8508 lags the directedvelocity 8506 by S3₁ and lags the directed velocity 8506 by a cumulativeerror C3₁ over a time period and the rate of change of the actualvelocity 8508 is R3₁. As the I-beam 2514 advances distally, the actualvelocity 8508 approaches the directed velocity 8506 at a rate of R3₂decreasing the lag error to S3₂ and increasing the cumulative error byC3₂ over a time period. As the I-beam 2514 advances towards the end ofstroke, the actual velocity 8508 overshoots N3₁, N3₂, N3₃ . . . N3_(n)the directed velocity 8506 and eventually settles at the directedvelocity 8506.

In another aspect, the control system of the surgical instrument 2500employs PID control errors to control motor velocity based on themagnitude of the PID error terms S, C, R, N over the I-beam 2514 stroke.As the I-beam 2514 traverses the staple cartridge 2528 a change indirected velocity 8506 may be based on measured errors between theactual velocity 8508 and the directed velocity 8506. For example, in thevelocity control system of the surgical instrument 2500, an error termis created between the directed velocity 8506 and the actual measuredvelocity 8508. The magnitude of these error terms can be used to set anew directed velocity 8506. The error terms of interest may include, forexample, short term, steady state, and accumulated. Different errorterms can be used in different zones 8516, 8518, 8520 (e.g., climbingthe ramp, intermediate, final). Different error terms can be magnifieddifferently based on their importance within the algorithm.

FIG. 18 is a graph 8530 of velocity (v) of a displacement member as afunction of displacement (δ) of the displacement member depictingcondition for threshold change of the directed velocity 8506-1 accordingto one aspect of this disclosure. In the illustrated aspect, thedisplacement (δ) (mm) of the I-beam 2514 is shown along the horizontalaxis 8532 and velocity (v) (mm/sec) of the I-beam 2514 is shown alongthe vertical axis 8534. In accordance with FIG. 18, the velocity controlsystem of the surgical instrument 2500 can be configured to measure theerror between the directed velocity of the I-beam 2514 and the actualvelocity 8508 of the I-beam 2514 and adjust the directed velocity 8506based on the magnitude of the error. As shown in FIG. 18, at δ₀ thedirected velocity 8506-1 and the actual velocity 8508 are about thesame. However, as the I-beam 2514 advances distally, due to outsidetissue influences, the actual velocity deviates from the directedvelocity 8506-1. The velocity control system of the surgical instrument2500 measures the position and timing of the I-beam 2514 using theposition sensor 2534 and the timer/counter 2531 to determine theposition and the actual velocity 8508 of the I-beam 2514 and at eachpredetermined position, the velocity control system determines the errorbetween the directed velocity of the I-beam 2514 and the actual velocity8508 of the I-beam 2514 and compares the error to a threshold. Forexample, at δ₁ the control circuit 2510 conducts a first errormeasurement and determines the lag S2₁ between the actual velocity 8508and the directed velocity 8506-1, the accumulated error C2₁, and therate of change R2₁. Based on the error measurements at δ₁ the controlcircuit 2510 determines that the magnitude of the error is within theerror threshold 8536 and maintains the current directed velocity 8506-1.At δ₂ the control circuit 2510 conducts another error measurement anddetermines the lag S2₂ between the actual velocity 8508 and the directedvelocity 8506-1, the accumulated error C2₂, and the rate of change R2₂.Based on the error measurements at δ₂ the control circuit 2510determines that the magnitude of the error exceeds the error threshold8536 and lowers the directed velocity to a new directed velocity 8506-2.This process is repeated until the measured error falls with thethreshold 8536 and the directed velocity may be adjusted back to theoriginal directed velocity 8506-1 or to a new directed velocity 8506-n.It will be appreciated that multiple error thresholds may be employed atdifferent I-beam 2514 displacement positions during the firing stroke.

In one aspect, the velocity error between the actual velocity 8508 andthe directed velocity 8506 of the displacement member (e.g., I-beam2514) V_(DM) can be represented by Eq. 1:

$\begin{matrix}{V_{DM} = {{A \cdot S} + {B \cdot {\sum C}} + {D \cdot \frac{\Delta\; R}{\Delta\; t}}}} & {{Eq}.\mspace{14mu} 1}\end{matrix}$Where A, B, and D are coefficients and S is the short term error, C isthe cumulative error, and R is the rate of change error. With referenceto FIG. 18, if the sum of the errors is less than the error threshold Zas represented by Eq. 2:S2₁ +C2₁ +R2₁ <Z  Eq. 2The control circuit 2510 determines that the error is within thethreshold Z and does not in the directed velocity 8506. Accordingly, thedirected velocity 8506-1 is maintained until the next predeterminedposition of the I-beam 2514. If the sum of the errors is greater thanthe error threshold Z as represented by Eq. 3:S2₂ +C2₂ +R2₂ >Z  Eq. 3The control circuit 2510 determines that the error is outside thethreshold Z and adjusts the directed velocity 8506 to a lower directedvelocity 8506-2.

FIG. 19 is a graph 8540 that illustrates the conditions for changing thedirected velocity 8506 of a displacement member according to one aspectof this disclosure. In the illustrated aspect, the displacement of theI-beam 2514 is shown along the horizontal axis 8541 and the cumulativeerror (S+C+R) is shown along the vertical axis 8544. An error curve 8546represents the change in the cumulative error as a function of I-beam2514 displacement. Marked along the vertical axis 8544 are various errorthresholds −Y, −Z, 0, +Z, +Y. As the error curve 8546 traverses thevarious error thresholds −Y, −Z, 0, +Z, +Y, the control circuit 2510 ofthe velocity control system of the surgical instrument 2500 shifts to anew directed velocity at a different rate or does not shift andmaintains the current directed velocity. A cumulative error of 0 alongthe horizontal axis 8542 represents the condition where there is nodifference between the directed velocity and the actual velocity of theI-beam 2514. When the cumulative error is within the ±Z errorthresholds, the control circuit 2510 of the velocity control systemmakes no adjustments to the directed velocity. If the cumulative erroris between the Z and Y thresholds or between the −Z and −Y thresholds,the control circuit 2510 of the velocity control system shifts to a newdirected velocity at a first shift rate indicate din the graph 8540 asShift Rate 1. If the cumulative error exceeds the ±Y error thresholds,the control circuit 2510 shifts to a new directed velocity at a secondshift rate indicated in the graph 8540 as Shift Rate 2, where Shift Rate2 is greater than Shift Rate 1, for example.

Still with reference to the graph 8540 in FIG. 19, the control circuit2510 of the velocity control system of the surgical instrument 2500takes no action during an initial displacement of the I-beam 2514between δ₀ and δ₁. Accordingly, during the initial displacement (δ₁-δ₀),the cumulative error 8548 returns to zero as the actual velocityapproaches the directed velocity and remains around zero until δ₂. Afterδ₂ the cumulative error 8550 deviates from zero until it exceeds the −Zthreshold at δ₃. Upon exceeding the −Z threshold, the control circuit2510 adjusts the velocity of the I-beam 2514 to a new directed velocityat Shift Rate 1. The cumulative error 8552 eventually returns to zeroand remains around zero until δ₄. Between δ₄ and δ₅ the cumulative error8554 deviates from zero and exceeds the +Y error threshold and at δ₅ thecontrol circuit 2510 adjusts the velocity of the I-beam 2514 to a newdirected velocity at Shift Rate 2, which is greater the Shift Rate 1.Upon adjusting the directed velocity of Shift Rate 2, the cumulativeerror 8556 returns to zero. Different error terms (S, C, R) can bemagnified differently based on their importance with an algorithm anddifferent error terms (S, C, R) can be employed in different zones,e.g., zones 8516, 8518, 8520 in FIG. 17, (e.g., climbing the ramp,intermediate, final).

FIG. 20 is a logic flow diagram of a process 8600 depicting a controlprogram or a logic configuration for controlling velocity of adisplacement member based on the position of a displacement member andthe actual velocity of the displacement member according to one aspectof this disclosure. With reference also to the velocity control systemof the surgical instrument 2500 shown in FIG. 14, the control circuit2510 determines 8602 the position of a displacement member such as theI-beam 2514 utilizing the position sensor 2534 and the timer/counter2531 circuits. The control circuit 2510 compares the position of thedisplacement member to one of a plurality of zones 8516, 8518, 8520 asdiscussed in connection with FIG. 17. The zones 8516, 8518, 8520 may bestored in memory. The control circuit 2510 determines 8604 in which zone8516, 8518, 8520 the displacement member is located in based on theposition of the displacement member previously determined 8602. Thecontrol circuit 2510 then sets 8606 the motor set point 2522 velocityand the motor control 2508 sets the motor drive signal 2524 to set themotor 254 velocity to achieve the desired directed velocity of thedisplacement member based on the zone. In one aspect, the motor control2508 sets the motor drive signal 2524 to a duty cycle based on whichzone 8516, 8518, 8520 the displacement member is located. The controlcircuit 2510 determines 8608 if the displacement member is at the end ofstroke. If the displacement member is not at the end of stroke, theprocess 8600 continues along the N branch and determines 8602 a newposition of the displacement member. The process 8600 continues untilthe displacement member reaches the end of stroke and proceeds along theYES branch and ends 8610.

FIG. 21 is a logic flow diagram of a process 8600 depicting a controlprogram or a logic configuration for controlling velocity of adisplacement member based on the measured error between the directedvelocity of a displacement member and the actual velocity of thedisplacement member according to one aspect of this disclosure. Withreference also to the velocity control system of the surgical instrument2500 shown in FIG. 14, the control circuit 2510 determines 8702 theposition of a displacement member such as the I-beam 2514 utilizing theposition sensor 2534 and the timer/counter 2531 circuits. The controlcircuit 2510 then determines 8704 the actual velocity of thedisplacement member based on the position information received from theposition sensor 2534 and the timer/counter 2531 circuits. Upondetermining 8704 the actual velocity of the displacement member, thecontrol circuit 2510 compares 8706 the directed velocity of thedisplacement member to the actual velocity of the displacement member.Based on the comparison 8706, the control circuit 2510 determines 8708the error between the directed velocity of the displacement member tothe actual velocity of the displacement member and compares 8710 theerror to an error threshold.

The error may be calculated based on Eq. 1 above. The control circuit2510 determines 8712 if the error is within the error threshold. If theerror is within the error threshold (Eq. 2), the process 8700 continuesalong the YES branch and maintains 8714 the directed velocity at itspresent value. The control circuit 2510 then determines 8718 if thedisplacement member is at the end stroke. If the displacement member isat the end of stroke, the process 8700 continues along the YES branchand ends 8720. If the displacement member is not at the end of stroke,the process 8700 continues along the NO branch and determines 8702 thenew position of the displacement member. The process 8700 continuesuntil the displacement member reaches the end of stroke.

If the error exceeds the error threshold (Eq. 3), the process 8700continues along the NO branch and adjusts the directed 8716 the directedvelocity to a new value. The new directed velocity may be higher orlower than the current directed velocity of the displacement member. Thecontrol circuit 2510 then determines 8718 if the displacement member isat the end stroke. If the displacement member is at the end of stroke,the process 8700 continues along the YES branch and ends 8720. If thedisplacement member is not at the end of stroke, the process 8700continues along the NO branch and determines 8702 the new position ofthe displacement member. The process 8700 continues until thedisplacement member reaches the end of stroke.

FIG. 22 is a logic flow diagram of a process 8700 depicting a controlprogram of logic configuration for controlling velocity of adisplacement member based on the measured error between the directedvelocity of a displacement member and the actual velocity of thedisplacement member according to one aspect of this disclosure. Withreference also to the velocity control system of the surgical instrument2500 shown in FIG. 14, the control circuit 2510 determines 8802 theposition of a displacement member such as the I-beam 2514 utilizing theposition sensor 2534 and the timer/counter 2531 circuits. The controlcircuit 2510 then determines 8804 the actual velocity of thedisplacement member based on the position information received from theposition sensor 2534 and the timer/counter 2531 circuits. Upondetermining 8804 the actual velocity of the displacement member, thecontrol circuit 2510 compares 8806 the directed velocity of thedisplacement member to the actual velocity of the displacement member.Based on the comparison 8806, the control circuit 2510 determines 8808the error between the directed velocity of the displacement member tothe actual velocity of the displacement member and compares 8810 theerror to multiple error thresholds. For example, in the illustratedexample, the error is compared to two error thresholds as described inconnection with FIG. 19.

The control circuit 2510 determines 8812 if the error is within thefirst error thresholds (±Z) as described in FIG. 19. If the error iswithin the first error thresholds (±Z), the process continues along theYES branch and the control circuit 2510 maintains 8814 the directedvelocity without any shift changes. The control circuit 2510 determines8816 if the displacement member is at the end of stroke. If thedisplacement member is at the end of stroke the process 8800 continuesalong the YES branch and ends 8824. If the displacement member is not atthe end of stroke, the process 8800 continues along the NO branch andthe control circuit 2510 determines 8802 the new position of thedisplacement member and the process 8800 continues until thedisplacement member reaches the end of stroke.

If the error is outside the first error thresholds (±Z) the process 8800continues along the NO branch and the control circuit 2510 determines8818 if the error exceeds the second error thresholds (±Y). If the errordoes not exceed the second error thresholds, the control circuit 2510determines that the error is between −Z and −Y or between +Z and +Yerror thresholds and proceeds along the NO branch and the controlcircuit 2510 adjusts 8820 the directed velocity at a first rate ofchange. The control circuit 2510 determines 8816 end of stroke andproceeds to determine 8802 the new position of the displacement member.The process 8800 continues until the displacement member reaches the endof stroke. If the error exceeds the second error thresholds, the controlcircuit 2510 determines that the error exceeds the second errorthresholds (±Y) and proceeds along the YES branch and the controlcircuit 2510 adjusts 8822 the directed velocity at a second rate ofchange, which is higher than the first rate change. In one aspect, thesecond rate of change is twice the first rate of change. It will beappreciated that the second rate of change may be greater than or lessthan the first rate of change. The control circuit 2510 determines 8816end of stroke and proceeds to determine 8802 the new position of thedisplacement member. The process 8800 continues until the displacementmember reaches the end of stroke. It will be appreciated that additionalerror thresholds and corresponding rates of change may be implemented.

Various aspects of the subject matter described herein are set out inthe following numbered examples:

Example 1

A surgical instrument, comprising: a displacement member configured totranslate within the surgical instrument over a plurality of predefinedzones; a motor coupled to the displacement member to translate thedisplacement member; a control circuit coupled to the motor; a positionsensor coupled to the control circuit, the position sensor configured tomeasure the position of the displacement member; and a timer circuitcoupled to the control circuit, the timer/counter circuit configured tomeasure elapsed time; wherein the control circuit is configured to:determine a position of the displacement member; determine a zone inwhich the displacement member is located; and set a directed velocity ofthe displacement member based on the zone in which the displacementmember is located.

Example 2

The surgical instrument of Example 1, wherein the control circuit isconfigured to: receive the position of the displacement member from theposition sensor; receive elapsed time from the timer circuit; and setduty cycle of the motor based on the zone in which the displacementmember is located.

Example 3

The surgical instrument of Example 2, wherein the control circuit isconfigured to determine an actual velocity of the displacement member.

Example 4

The surgical instrument of Example 3, wherein the control circuit isconfigured to determine an error between the directed velocity of thedisplacement member and the actual velocity of the displacement member.

Example 5

The surgical instrument of Example 4, wherein the control circuit isconfigured to set a new directed velocity of the displacement memberbased on the error.

Example 6

The surgical instrument of Example 4, wherein the error is based on atleast one of a short term error (S), cumulative error (C), rate ofchange error (R), and number of overshoots error (N).

Example 7

The surgical instrument of Example 1 through Example 6, comprising anend effector, wherein the displacement member is configured to translatewithin the end effector.

Example 8

A surgical instrument, comprising: a displacement member configured totranslate within the surgical instrument; a motor coupled to thedisplacement member to translate the displacement member; a controlcircuit coupled to the motor; a position sensor coupled to the controlcircuit, the position sensor configured to measure the position of thedisplacement member; and a timer circuit coupled to the control circuit,the timer/counter circuit configured to measure elapsed time; whereinthe control circuit is configured to: set a directed velocity of thedisplacement member; determine a position of the displacement member;determine actual velocity of the displacement member; compare directedvelocity of the displacement member to the actual velocity of thedisplacement member; determine error between the displacement member tothe actual velocity of the displacement member; and adjust the directedvelocity of the displacement member based on the error.

Example 9

The surgical instrument of Example 8, wherein the control circuit isconfigured to compare the error to an error threshold.

Example 10

The surgical instrument of Example 9, wherein the control circuit isconfigured to maintain the directed velocity of the displacement memberwhen the error is within the error threshold.

Example 11

The surgical instrument of Example 9 through Example 10, wherein thecontrol circuit is configured to adjust the directed velocity of thedisplacement member to change the directed velocity when the errorexceeds the error threshold.

Example 12

The surgical instrument of Example 8 through Example 11, wherein theactual velocity of the displacement member is given by the followingexpression:

$V_{DM} = {{A \cdot S} + {B \cdot {\sum C}} + {D \cdot \frac{\Delta\; R}{\Delta\; t}}}$where A, B, and D are coefficients and S is a short term error, C is acumulative error, and R is a rate of change error.

Example 13

The surgical instrument of Example 8 through Example 12, comprising anend effector, wherein the displacement member is configured to translatewithin the end effector.

Example 14

A surgical instrument, comprising: a displacement member configured totranslate within the surgical instrument; a motor coupled to thedisplacement member to translate the displacement member; a controlcircuit coupled to the motor; a position sensor coupled to the controlcircuit, the position sensor configured to measure the position of thedisplacement member; and a timer circuit coupled to the control circuit,the timer/counter circuit configured to measure elapsed time; whereinthe control circuit is configured to: set a directed velocity of thedisplacement member; determine a position of the displacement member;determine actual velocity of the displacement member; compare directedvelocity of the displacement member to the actual velocity of thedisplacement member; determine error between the displacement member tothe actual velocity of the displacement member; and adjust the directedvelocity of the displacement member at a rate of change based on theerror.

Example 15

The surgical instrument of Example 14, wherein the control circuit isconfigured to compare the error to multiple error thresholds.

Example 16

The surgical instrument of Example 15, wherein the control circuit isconfigured to adjust the directed velocity of the displacement member atmultiple rates of change based on the error.

Example 17

The surgical instrument of Example 15 through Example 16, wherein thecontrol circuit is configured to: compare the error to a first errorthreshold; and maintain the directed velocity when the error is withinthe first error threshold.

Example 18

The surgical instrument of Example 17, wherein the control circuit isconfigured to: compare the error to a second error threshold; adjust thedirected velocity at a first rate of change when the error exceeds thefirst error threshold and is within the second error threshold.

Example 19

The surgical instrument of Example 17 through Example 18, wherein thecontrol circuit is configured to: compare the error to a second errorthreshold; adjust the directed velocity at a second rate of change whenthe error exceeds both the first error threshold and the second errorthreshold.

Example 20

The surgical instrument of Example 14 through Example 19, wherein theerror is based on at least one of a short term error (S), cumulativeerror (C), rate of change error (R), and number of overshoots error (N).

Closed Loop Feedback Control of Motor Velocity of a Surgical Staplingand Cutting Instrument Based on Measured Time Over a SpecifiedDisplacement Distance

During use of a motorized surgical stapling and cutting instrument it ispossible that the velocity of the cutting member or the firing membermay need to be measured and adjusted to compensate for tissueconditions. In thick tissue the velocity may be decreased to lower theforce to fire experienced by the cutting member or firing member if theforce to fire experienced by the cutting member or firing member isgreater than a threshold force. In thin tissue the velocity may beincreased if the force to fire experienced by the cutting member orfiring member is less than a threshold. Therefore, it may be desirableto provide a closed loop feedback system that measures and adjusts thevelocity of the cutting member or the firing member based on ameasurement of time over a specified distance. It may be desirable tomeasure the velocity of the cutting member by measuring time at fixedset displacement intervals.

The disclosure now turns to a closed loop feedback system to providevelocity control of a displacement member. The closed loop feedbacksystem adjusts the velocity of the displacement member based on ameasurement of actual time over a specified distance or displacementinterval of the displacement member. In one aspect, the closed loopfeedback system comprises two phases. A start phase defined as the startof a firing stroke followed by a dynamic firing phase while the I-beam2514 advances distally during the firing stroke. FIGS. 23A and 23B showthe I-beam 2514 positioned at the start phase of the firing stroke. FIG.23A illustrates an end effector 2502 comprising a firing member 2520coupled to an I-beam 2514 comprising a cutting edge 2509. The anvil 2516is in the closed position and the I-beam 2514 is located in a proximalor parked position 9002 at the bottom of the closure ramp 9006. Theparked position 9002 is the position of the I-beam 2514 prior totraveling up the anvil 2516 closure ramp 9006 to the top of the ramp9006 to the T-slot 9008. A top pin 9080 is configured to engage a T-slot9008 and a lockout pin 9082 is configured to engage a latch feature9084.

In FIG. 23B the I-beam 2514 is located in a target position 9004 at thetop of the ramp 9006 with the top pin 2580 engaged in the T-slot 9008.As shown in FIGS. 23A-23B, in traveling from the parked position 9002 tothe target position 9004, the I-beam 2514 travels a distance indicatedas X₀ in the horizontal distal direction. During the start phase, thevelocity of the I-beam 2514 is set to a predetermined initial velocityV₀. A control circuit 2510 measures the actual time t₀ that it takes theI-beam 2514 to travel up the ramp 9006 from the parked position 9002 tothe target position 9004 at the initial velocity V₀. In one aspect, thehorizontal distance is 4.1 mm and the initial velocity V₀ is 12 mm/s. Asdescribed in more detail below, the actual time t₀ is used to set thecommand velocity of the I-beam 2514 to slow, medium, or fast in thesubsequent staple cartridge zone Z as the I-beam 2514 advances distally.The number of zones may depend on the length/size of the staplecartridge (e.g., 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, >60 mm). Thecommand velocity or set velocity is the velocity of the motor 2504 thatis applied to the motor 2504 by the control circuit 2510 and motorcontrol 2508 in order effect a desired velocity of the I-beam 2514. Theactual velocity of the I-beam 2514 is determined by the control circuit2510 by measuring the actual time t₀ with the timer/counter 2531 circuitthat it takes the I-beam 2514 to traverse a specified or fixed distanceprovided by the position sensor 2534. In accordance with one aspect ofthe present disclosure, the closed loop feedback control system of thesurgical instrument measures the actual time t_(n) it takes the I-beam2514, or a displacement member, to travel a predetermined fixed distanceor displacement interval X_(n). A predetermined fixed distance ordisplacement interval X_(n) is defined for each zone (e.g., Z₁, Z₂, Z₃ .. . Z_(n)).

FIG. 24 illustrates the I-beam 2514 firing stroke is illustrated by achart 9009 aligned with the end effector 2502 according to one aspect ofthis disclosure. As shown, the initial zone (Z₀), or base zone, isdefined as the distance traveled by the I-beam 2514 from the parkedposition 9002 to the target position 9004. The measured time T₀ is thetime it takes the I-beam 2514 to travel up the closure ramp 9006 to thetarget position 9004 at an initial set velocity V₀. The measured timesT₁-T₅ are reference periods of time for traversing the correspondingzones Z₁-Z₅, respectively. The displacement of the I-beam 2514 in zoneZ₀ is X₀. The period T₀, the time it takes for the I-beam 2514 to travelover a distance X₀, is used to set the command velocity in thesubsequent zone Z₁.

With reference now to FIGS. 14-15 and 23A-24, at the start phase, e.g.,at the beginning of a firing stroke, the control circuit 2510 isconfigured to initiate firing the displacement member, such as theI-beam 2514, at a predetermined velocity V₀ (e.g., 12 mm/s). During thestart phase, the control circuit 2510 is configured to monitor theposition of the I-beam 2514 and measure the time t₀ (sec) it takes forthe I-beam 2514 to travel from the I-beam 2514 parked position 9002 tothe I-beam 2514 target position 9004, either to the top of the anvil2516 closure ramp 9006, or at the end of a low power mode of operation.Time t₀ in the initial zone 9010 is used by the control circuit 2510 todetermine the firing velocity of the I-beam 2514 through the first zoneZ₁. For example, in one aspect, if time t₀ is <0.9 sec the velocity V₁may be set to fast and if time t₀≥0.9 sec the velocity may be set tomedium. Faster or slower times may be selected based on the length ofthe staple cartridge 2518. The actual time t₁-t₅ that it takes theI-beam 2514 to traverse a corresponding zone Z₁ to Z₅ is measured at acorresponding set displacement δ₁-δ₅ and is compared to a correspondingreference time period T₁-T₅. In various aspects, if a lockout conditionis encountered, the motor 2504 will stall before the I-beam 2514 reachesthe target position 9004. When this condition occurs, the surgicalinstrument display indicates the instrument status and may issue a stallwarning. The display also may indicate a speed selection.

During the dynamic firing phase, the surgical instrument enters thedynamic firing phase, where the control circuit 2510 is configured tomonitor the displacement interval δ_(n) of the I-beam 2514 and measurethe time t_(n) that it takes the I-beam 2514 to travel from thebeginning of a zone to the end of a zone (e.g., a total distance of 5 mmor 10 mm). In FIG. 24, the reference time T₁ is the time taken by theI-beam 2514 to travel from the beginning of zone Z₁ to the end of zoneZ₁ at a set velocity V₁. Likewise, the reference time T₂ is the time ittakes the I-beam 2514 to travel from the beginning of zone Z₂ to the endof zone Z₂ at a set velocity V₂, and so on. Table 1 shows zones that maybe defined for staple cartridges 2518 of various sizes.

TABLE 1 Defined Zones For Staple Cartridges Of Various Sizes ZonesStaple Cartridge Z₁ Z₂ Z₃ Z₄ Z₅ Z₆   35 mm 0-5 mm 5-15 mm 15-25 mm   >25mm N/A N/A 40-45 mm 0-5 mm 5-15 mm 15-25 mm 25-35 mm >35 mm N/A 55-60 mm0-5 mm 5-15 mm 15-25 mm 25-35 mm 35-45 mm   >45 mm

For staple cartridges 2518 over 60 mm, the pattern continues, but thelast 10-15 mm continues at a command or indicated velocity of theprevious zone pending other interventions for end of stroke, amongothers. At the end of each zone, the actual time t_(n) it took theI-beam 2514 to pass through the zone is compared to the values in othertables (e.g., Tables 2-5 below) to determine how to set the commandvelocity for the next zone. The command velocity is updated for the nextzone and the process continues. Whenever the command velocity isupdated, the next zone will not be evaluated. The end of stroke ishandled in accordance with a predetermined protocol/algorithm of thesurgical instrument including limit switches, controlled deceleration,etc. At the end of stroke, the I-beam 2514 is returned to the initialI-beam park position 9002 at the fast speed. End of return stroke(returning to the parked position 9002) is handled in accordance withthe protocol/algorithm of the surgical instrument. Other zones may bedefined without limitation.

TABLE 2 Time To Travel Through Zones At Specified Command Velocity ForVarious Dynamic Firing Zones Time (sec) to Travel Through Zone atSpecified Command Velocity Dynamic Firing Zone (mm) Fast Medium SlowFirst Zone (X₁ mm long) t < t₁ t₁ < t < t₂ t > t₂ Intermediate Zones (X₂mm long) t < t₃ t₃ < t < t₄ t > t₄ Last Measured Zone (X₃ mm long) t <t₅ t₅ < t < t₆ t > t₆

TABLE 3 Non-limiting Examples Of Time To Travel Through Zones AtSpecified Command Velocity For Various Dynamic Firing Zones Time (sec)to Travel Through Zone at Specified Command Velocity Dynamic Firing Zone(mm) Fast Medium Slow First Zone (5 mm long) t < 0.5 0.5 < t < 0.6 t >0.6 Intermediate Zones (10 mm long) t < 0.9 0.9 < t < 1.1 t > 1.1 LastMeasured Zone (10 mm long) t < 1.0 1.0 < t < 1.3 t > 1.3

TABLE 4 Algorithm To Set Velocity Based On Time To Travel Up RampAlgorithm t_(a) (sec) t_(b) (sec) If time t (sec) for I-beam to travelt₁ < t < t₂ t > t₂ to t₃ up ramp is . . . Then initial velocity V ofI-beam in V₁ (mm/sec) V₂ (mm/sec) T-slot is . . . And automatic velocityis set at . . . FAST MEDIUM

TABLE 5 Non-limiting Example Of Algorithm To Set Velocity Based On TimeTo Travel Up Ramp Algorithm t_(a) (sec) t_(b) (sec) If time t (sec) forI-beam to travel 0.0 < t < 0.9 t > 0.9 to 1.8 up ramp is . . . Theninitial velocity of I-beam in 30 mm/sec 12 mm/sec T-slot is . . . Andautomatic velocity is set at . . . FAST MEDIUM

In one aspect, Tables 1-5 may be stored in memory of the surgicalinstrument. The Tables 1-5 may be stored in memory in the form of alook-up table (LUT) such that the control circuit 2510 can retrieve thevalues and control the command velocity of the I-beam 2514 in each zonebased on the values stored in the LUT.

FIG. 25 is a graphical depiction 9100 comparing the I-beam 2514 strokedisplacement interval δ_(n) as a function of time 9102 (top graph) andexpected force-to-fire the I-beam 2514 as a function of time 9104(bottom graph) according to one aspect of this disclosure. Referring tothe top graph 9102, the horizontal axis 9106 represents time (t) inseconds (sec) from 0-1.00×, where X is a scaling factor. For example, inone aspect, X=6 and the horizontal axis 9106 represents time from 0-6sec. The vertical axis 9108 represents displacement (δ) of the I-beam2514 in millimeters (mm). The displacement interval δ₁ represents theI-beam 2615 stroke 9114 or displacement at the top of the ramp 9006(FIGS. 23A, 23B) for thin tissue and medium thick tissue. The time forthe I-beam 2514 to reach the top of ramp stroke 9114 for thin tissue ist₁ and the time for the I-beam 2514 to reach the top of ramp stroke 9114for medium thick tissue is t₂. As shown, t₁<t₂, such that it takes lesstime for the I-beam 2514 to reach the top of the ramp stroke 9114 forthin tissue as it takes for medium or thick tissue. In one example, thetop of ramp stroke 9114 displacement interval δ₁ is about 4.1 mm (01.60inches) and the time t₁ is less than 0.9 sec (t₁<0.9 sec) and the timet₂ is greater than 0.9 sec but less than 1.8 sec (0.9<t₂<1.8 sec).Accordingly, with reference also to Table 5, the velocity to reach thetop of ramp stroke 9114 is fast for thin tissue and medium for mediumthick tissue.

Turning now to the bottom graph 9104, the horizontal axis 9110represents time (t) in seconds (sec) and has the same scale of thehorizontal axis 9106 of the top graph 9102. The vertical axis 9112,however, represents expected force to fire (F) the I-beam 2514 innewtons (N) for thin tissue force to fire graph 9116 and medium thicktissue force to fire graph 9118. The thin tissue force to fire graph9116 is lower than medium thick tissue force to fire graph 9118. Thepeak force F₁ for the thin tissue force to fire graph 9116 is lower thanthe peak force F₂ for the medium thick tissue to fire graph 9118. Also,with reference to the top and bottom graphs 9102, 9104, the initialvelocity of the I-beam 2514 in zone Z₀ can be determined based onestimated tissue thickness. As shown by the thin tissue force to firegraph 9116, the I-beam 2514 reaches the peak force F₁ top of ramp stroke9114 at a fast initial velocity (e.g., 30 mm/sec) and as shown by themedium thick tissue force to fire graph 9118, the I-beam 2514 reachesthe peak force F₂ top of ramp stroke 9114 at a medium initial velocity(e.g., 12 mm/sec). Once the initial velocity in zone Z₀ is determined,the control circuit 2510 can set the estimated velocity of the I-beam2514 in zone Z₁, and so on.

FIG. 26 is a graphical depiction 9200 comparing tissue thickness as afunction of set displacement interval of I-beam stroke 9202 (top graph),force to fire as a function of set displacement interval of I-beamstroke 9204 (second graph from the top), dynamic time checks as afunction of set displacement interval of I-beam stroke 9206 (third graphfrom the top), and set velocity of I-beam as a function of setdisplacement interval of I-beam stroke 9208 (bottom graph) according toone aspect of this disclosure. The horizontal axis 9210 for each of thegraphs 9202, 9204, 9206, 9208 represents set displacement interval of anI-beam 2514 stroke for a 60 mm staple cartridge, for example. Withreference also to Table 1, the horizontal axis 9210 has been marked toidentify the defined zones Z₁-Z₆ for a 60 mm staple cartridge. Asindicated in Table 1, the defined zones may be marked for staplecartridges of various sizes. With reference also to FIG. 14, inaccordance with the present disclosure, the control circuit 2510 samplesor measures the elapsed time from the timer/counter circuit 2531 at setI-beam 2514, or other displacement member, displacement intervals alongthe staple cartridge 2518 during the firing stroke. At set displacementintervals δ_(n) received from the position sensor 2534, the controlcircuit 2510 samples or measures the elapsed time t_(n) it took theI-beam 2514 to travel the fixed displacement intervals δ_(n). In thismanner, the control circuit 2510 can determine the actual velocity ofthe I-beam 2514 and compare the actual velocity to the estimatedvelocity and make any necessary adjustments to the motor 2504 velocity.

The tissue thickness graph 9202 shows a tissue thickness profile 9220along the staple cartridge 2518 and an indicated thickness 9221 as shownby the horizontal dashed line. The force to fire graph 9204 shows theforce to fire profile 9228 along the staple cartridge 2518. The force tofire 9230 remains relatively constant while the tissue thickness 9222remains below the indicated thickness 9221 as the I-beam 2514 traversezones Z₁ and Z₂. As the I-beam 2514 enters zone Z₃, the tissue thickness9224 increases and the force to fire also increase while the I-beam 2514traverses the thicker tissue in zones Z₃, Z₄, and Z₅. As the I-beam 2514exits zone Z₅ and enters zone Z₆, the tissue thickness 9226 decrease andthe force to fire 9234 also decreases.

With reference now to FIGS. 14, 24-26 and Tables 2-3, the velocity V₁ inzone Z₁ is set to the command velocity V₀ determined by the controlcircuit 2510 in zone Z₀, which is based on the time it takes the I-beam2514 to travel to the top of the ramp 9006 in zone Z₀ as discussed inreference to FIGS. 23A, 23B, and 25. Turning also to the graphs 9206,9208 in FIG. 26, the initial set velocity V₀ was set to Medium and thusthe set velocity V₁ in zone Z₁ is set to Medium such that V₁=V₀.

At set displacement position δ₁ (e.g., 5 mm for a 60 mm staplecartridge), as the I-beam 2514 exits zone Z₁ and enters zone Z₂, thecontrol circuit 2510 measures the actual time t₁ that it takes theI-beam 2514 to traverse the set displacement interval X₁ (5 mm long) anddetermines the actual velocity of the I-beam 2514. With reference tographs 9206 and 9208 in FIG. 26, at set displacement position δ₁, theactual time t₁ it takes the I-beam 2514 to travel the set displacementinterval X₁ is t₁=0.55 sec. According to Table 3, an actual travel timet₁=0.55 sec in zone Z₁ requires the command or set velocity V₂ in zoneZ₂ to be set to Medium. Accordingly, the control circuit 2510 does notreset the command velocity for zone Z₂ and maintains it at Medium.

At set displacement position δ₂ (e.g., 15 mm for a 60 mm staplecartridge), as the I-beam 2514 exits zone Z₂ and enters zone Z₃, thecontrol circuit 2510 measures the actual time t₂ it takes the I-beam2514 to traverse the set displacement interval X₂ (10 mm long) anddetermines the actual velocity of the I-beam 2514. With reference tographs 9606 and 9608 in FIG. 26, at set displacement position δ₂, theactual time t₂ it takes the I-beam 2514 to travel the set displacementinterval X₂ is t₂=0.95 sec. According to Table 3, an actual travel timet₂=0.95 sec in zone Z₂ requires the command or set velocity V₃ in zoneZ₃ to be set to Medium. Accordingly, the control circuit 2510 does notreset the command velocity for zone Z₃ and maintains it at Medium.

At set displacement position δ₃ (e.g., 25 mm for a 60 mm staplecartridge), as the I-beam 2514 exits zone Z₃ and enters zone Z₄, thecontrol circuit 2510 measures the actual time t₃ it takes the I-beam2514 to traverse the set displacement interval X₃ (10 mm long) anddetermines the actual velocity of the I-beam 2514. With reference tographs 9606 and 9608 in FIG. 26, at set displacement position δ₃, theactual time t₃ it takes the I-beam 2514 to travel the set displacementinterval X₃ is t₃=1.30 sec. According to Table 3, an actual travel timet₃=1.30 sec in zone Z₃ requires the command or set velocity V₄ in zoneZ₄ to be set to Slow. This is because the actual travel time of 1.3 secis greater than 1.10 sec and is outside the previous range. Accordingly,the control circuit 2510 determines that the actual I-beam 2514 velocityin zone Z₃ was slower than expected due to external influences such asthicker tissue than expected as shown in tissue region 9224 in graph9202. Accordingly, the control circuit 2510 resets the command velocityV₄ in zone Z₄ from Medium to Slow.

In one aspect, the control circuit 2510 may be configured to disablevelocity reset in a zone following a zone in which the velocity wasreset. Stated otherwise, whenever the velocity is updated in a presentzone the subsequent zone will not be evaluated. Since the velocity wasupdated in zone Z₄, the time it takes the I-beam 2514 to traverse zoneZ₄ will not be measured at the end of zone Z₄ at the set displacementdistance δ₄ (e.g., 35 mm for a 60 mm staple cartridge). Accordingly, thevelocity in zone Z₅ will remain the same as the velocity in zone Z₄ anddynamic time measurements resume at set displacement position δ₅ (e.g.,45 mm for a 60 mm staple cartridge).

At set displacement position δ₅ (e.g., 45 mm for a 60 mm staplecartridge) as the I-beam 2514 exits zone Z₅ and enters zone Z₆, thecontrol circuit 2510 measures the actual time t₅ it takes the I-beam2514 to traverse the set displacement interval X₅ (10 mm long) anddetermines the actual velocity of the I-beam 2514. With reference tographs 9606 and 9608 in FIG. 26, at set displacement position δ₅, theactual time t₅ it takes the I-beam 2514 to traverse the set displacementinterval X₅ is t₅=0.95 sec. According to Table 3, an actual travel timeof t₅=0.95 sec in zone Z₅ requires the command or set velocity V₆ inzone Z₆ to be set to High. This is because the actual travel time of0.95 sec is less than 1.00 sec is outside the previous range.Accordingly, the control circuit 2510 determines that the actualvelocity of the I-beam 2514 in zone Z₅ was faster than expected due toexternal influences such as thinner tissue than expected as shown intissue region 9626 in graph 9602. Accordingly, the control circuit 2510resets the command velocity V₆ in zone Z₆ from Slow to High.

FIG. 27 is a graphical depiction 9300 of force to fire as a function oftime comparing slow, medium and fast I-beam 2514 displacement velocitiesaccording to one aspect of this disclosure. The horizontal axis 9302represents time t (sec) that it takes an I-beam to traverse a staplecartridge. The vertical axis 9304 represents force to fire F (N). Thegraphical depiction shows three separate force to fire curves versustime. A first force to fire curve 9312 represents an I-beam 2514 (FIG.14) traversing through thin tissue 9306 at a fast velocity and reachinga maximum force to fire F₁ at the top of the ramp 9006 (FIG. 23B) at t₁.In one example, a fast traverse velocity for the I-beam 2514 is ˜30mm/sec. A second force to fire curve 9314 represents an I-beam 2514traversing through medium tissue 9308 at a medium velocity and reachinga maximum force to fire F₂ at the top of the ramp 9006 at t₂, which isgreater than t₁. In one example, a medium traverse velocity for theI-beam 2514 is ˜12 mm/sec. A third force to fire curve 9316 representsan I-beam 2514 traversing through thick tissue 9310 at a slow velocityand reaching a maximum force to fire F₃ at the top of the ramp 9006 att₃, which is greater than t₂. In one example, a slow traverse velocityfor the I-beam 2514 is ˜9 mm/sec.

FIG. 28 is a logic flow diagram of a process 9400 depicting a controlprogram or logic configuration for controlling command velocity in aninitial firing stage according to one aspect of this disclosure. Withreference also to FIGS. 14 and 23A-27, the control circuit 2510determines 9402 the reference position of the displacement member, suchas the I-beam 2514, for example, based on position information providedby the position sensor 2534. In the I-beam 2514 example, the referenceposition is the proximal or parked position 9002 at the bottom of theclosure ramp 9006 as shown in FIG. 23B. Once the reference position isdetermined 9402, the control circuit 2510 and motor control 2508 set thecommand velocity of the motor 2504 to a predetermined command velocityV₀ and initiates 9404 firing the displacement member (e.g., I-beam 2514)at the predetermined command velocity V₀ for the initial or base zoneZ₀. In one example, the initial predetermined command velocity V₀ is ˜12mm/sec, however, other initial predetermined command velocity V₀ may beemployed. The control circuit 2510 monitors 9406 the position of thedisplacement member with position information received from the positionsensor 2534 until the I-beam 2514 reaches a target position at the topof the ramp 9006 as shown in FIG. 23B. The predetermined displacementperiod T₀ is the expected displacement period of the displacement membertraveling at the current set command velocity V₀. The deviation betweenactual displacement period T_(n) and the predetermined displacementperiod T₀ is due at least in part to external influences acting on thedisplacement member such as tissue thickness acting on the cutting edge2509 of the I-beam 2514.

With timing information received from the timer/counter circuit 2531 andposition information received from the position sensor 2534, the controlcircuit 2510 measures 9408 the time t₀ it takes the displacement memberto travel from the reference position 9002 to the target position 9004.The control circuit 210 sets 9410 the command velocity V₁ for the firstzone Z₁ based on the measured time t₀. As indicated in Table 1, variousdefined zones may be defined for staple cartridges of various sizes.Other zones, however, may be defined. The control circuit 2510 sets 9410the command velocity V₁ for the first zone Z₁ by comparing 9412 themeasured time t₀ to values stored in memory, such as, for example,stored in a lookup table (LUT). In one example, as indicated in Table 4generally and in Table 5 by way of specific example, if the time t₀ ittakes the I-beam 2514 to travel up the ramp 9006 from the referenceposition 9002 to the target position 9004 is between 0.0 and 0.9 sec(0.0 sec <t₀<0.9 sec), then the command velocity for the first zone Z₁is set 9414 to FAST (e.g., 30 mm/sec). Otherwise, if the time t₀ (sec)for the I-beam 2514 to travel up the ramp 9006 from the referenceposition 9002 to the target position 9004 is greater than 0.9 sec to 1.8sec (t₀>0.9 sec to 1.8 sec), then the command velocity for the firstzone Z₁ is set 9416 to MEDIUM (e.g., 12 mm/sec). Subsequently, thecontrol circuit 2510 checks 9418 for lockout and stops 9420 the motor2504 if there is a lockout condition. Otherwise, the control circuitenters 9422 the dynamic firing phase as described below in reference toprocess 9450 in FIG. 29.

FIG. 29 is a logic flow diagram of a process 9450 depicting a controlprogram or logic configuration for controlling command velocity in adynamic firing stage according to one aspect of this disclosure. Withreference also to FIGS. 14 and 23A-27, the control circuit 2510 sets9452 the initial command velocity of the motor 2504 for the first zoneZ₁ based on the initial time t₀, as described in reference to theprocess 9400 in FIG. 28. As the displacement member traverses the staplecartridge 2518, the control circuit 2510 receives the position of thedisplacement member from the position sensor 2534 and timing informationfrom the timer/counter 2531 circuit and monitors 9454 the position ofthe displacement member over the predefined zone Z_(n). At the end ofthe zone Z_(n), the control circuit 2510 measures 9456 the actual timet_(n) the displacement member took to travel from the beginning of thezone Z_(n) to the end of the zone Z_(n) and compares 9458 the actualtime t_(n) to a predetermined time for a particular zone as showngenerally in Table 2 and by way of specific example in Table 3. Thepredetermined displacement period T_(n) is the expected displacementperiod of the displacement member traveling at the current set commandvelocity V_(n). The deviation between actual displacement period t_(n)and the predetermined displacement period T_(n) is due at least in partto external influences acting on the displacement member such as tissuethickness acting on the cutting edge 2509 of the I-beam 2514.

For example, with reference to Table 3 the time to travel through a zoneat specified command velocity is provided for various dynamic firingzones. For example, if the dynamic firing zone is the zone Z₁ (5 mmlong) and t_(n)<0.5 sec, the command velocity for the next zone Z₂ isset to FAST; if 0.5<t_(n)<0.6 sec, the command velocity for the nextzone Z₂ is set to MEDIUM; and if t_(n)>0.6 sec, the command velocity forthe next zone Z₂ is set to SLOW.

If, however, the dynamic firing zone is an intermediate zone Z₂-Z₅ (10mm long), for example, located between the first zone Z₁ and the lastzone Z₆ and if t_(n)<0.9 sec, the command velocity for the next zone Z₂is set to FAST; if 0.9<t_(n)<1.1 sec, the command velocity for the nextzone Z₃-Z₅ is set to MEDIUM; and if t_(n)>1.1 sec, the command velocityfor the next zone Z₃-Z₅ is set to SLOW.

Finally, if the dynamic firing zone is the last measured zone Z₅ (10 mmlong) and t_(n)<1.0 sec, the command velocity for the final zone Z₆ isset to FAST; if 1.0<t_(n)<1.3 sec, the command velocity for the finalzone Z₆ is set to MEDIUM; and if t_(n)>1.3 sec, the command velocity forthe final zone Z₆ is set to SLOW. Other parameters may be employed notonly to define the dynamic firing zones but also to define the time totravel through a zone at specified command velocity for various dynamicfiring zones.

Based on the results of the comparison 9458 algorithm, the controlcircuit 2510 will continue the process 9450. For example, if the resultsof the comparison 9458 indicate that the actual velocity (FAST, MEDIUM,SLOW) in the previous zone Z_(n) is the same as the previous commandvelocity V₁ (FAST, MEDIUM, SLOW), the control circuit 2510 maintains9460 the command velocity V₁ for the next zone Z_(n+1) the same as theas the previous command velocity V₁. The process 9450 continues tomonitor 9454 the position of the displacement member over the nextpredefined zone Z_(n+1). At the end of the next zone Z_(n+1), thecontrol circuit 2510 measures 9456 the time t_(n+1) the displacementmember took to travel from the beginning of the next zone Z_(n+1) to theend of the next zone Z_(n1) and compares 9458 the actual time t_(n+1) toa predetermined time for a particular zone as shown generally in Table 2and by way of specific example in Table 3. If there are no changesrequired to the command velocity, the process 9450 until thedisplacement member, e.g., the I-beam 2514, reaches the end of stroke9466 and returns 9468 the displacement member to the reference position9002.

If the results of the comparison 9458 indicate that the actual velocity(FAST, MEDIUM, SLOW) in the previous zone Z_(n) is different as theprevious command velocity V₁ (FAST, MEDIUM, SLOW), the control circuit2510 resets 9462 or updates the command velocity to V_(new) for the nextzone Z_(n+1) according to the algorithm summarized in Tables 2 and 3. Ifthe command velocity is reset 9462 or updated, the control circuit 2510maintains 9464 the command velocity V_(new) for an additional zoneZ_(n+2). In other words, at the end of the next zone Z_(n+1), thecontrol circuit 2510 does not evaluate or measure the time. The process9450 continues to monitor 9454 the position of the displacement memberover the next predefined zone Z_(n+1) until the displacement member,e.g., the I-beam 2514, reaches the end of stroke 9466 and returns 9468the displacement member to the reference position 9002.

Various aspects of the subject matter described herein are set out inthe following numbered examples:

Example 1

A surgical instrument, comprising: a displacement member configured totranslate within the surgical instrument over a plurality of predefinedzones; a motor coupled to the displacement member to translate thedisplacement member; a control circuit coupled to the motor; a positionsensor coupled to the control circuit, the position sensor configured tomonitor the position of the displacement member; a timer circuit coupledto the control circuit, the timer/counter circuit configured to measureelapsed time; wherein the control circuit is configured to: receive,from the position sensor, a position of the displacement member in acurrent zone defined by a set displacement interval; measure time at aset position of the displacement interval, wherein the measured time isdefined as the time taken by the displacement member to traverse thedisplacement interval; and set a command velocity of the displacementmember for a subsequent zone based on the measured time in the currentpredefined zone.

Example 2

The surgical instrument of Example 1, wherein the control circuit isconfigured to: determine the set displacement interval in which thedisplacement member is located, wherein the set displacement interval isdefined by a beginning position and an ending position; and measure thetime when the displacement member reaches the ending position of thedisplacement interval.

Example 3

The surgical instrument of Example 1 through Example 2, wherein thecontrol circuit is configured to: compare the measured time to apredetermined time stored in a memory coupled to the control circuit;and determine whether to adjust or maintain the command velocity basedon the comparison.

Example 4

The surgical instrument of Example 3, wherein the control circuit isconfigured to maintain the command velocity for the subsequent zone thesame as the command velocity of the current zone when the measured timeis within a range of predetermined times.

Example 5

The surgical instrument of Example 3 through Example 4, wherein thecontrol circuit is configured to set the command velocity for thesubsequent zone different from the command velocity of the current zonewhen the measured time is outside a range of predetermined times.

Example 6

The surgical instrument of Example 5, wherein the control circuit isconfigured to skip a time measurement for a subsequent zone when thecommand velocity is adjusted.

Example 7

The surgical instrument of Example 1 through Example 6, wherein multiplezones are defined for a staple cartridge configured to operate with thesurgical instrument.

Example 8

The surgical instrument of Example 7, wherein at least two zones have adifferent length.

Example 9

A surgical instrument, comprising: a displacement member configured totranslate within the surgical instrument over a plurality of predefinedzones; a motor coupled to the displacement member to translate thedisplacement member; a control circuit coupled to the motor; a positionsensor coupled to the control circuit, the position sensor configured tomonitor the position of the displacement member; a timer circuit coupledto the control circuit, the timer/counter circuit configured to measureelapsed time; wherein the control circuit is configured to: receive,from the position sensor, a position of the displacement member in acurrent zone defined by a predetermined displacement interval; measuretime as the displacement member moves from a parked position to a targetposition; and set a command velocity of the displacement member for afirst dynamic zone based on the measured time.

Example 10

The surgical instrument of Example 9, wherein the control circuit isconfigured to compare the measured time to a predetermined time storedin a memory coupled to the control circuit.

Example 11

The surgical instrument of Example 10, wherein the control circuit isconfigured to set the command velocity for the initial zone to a firstvelocity when the measured time is within a first range of times and setthe command velocity for the initial zone to a second velocity when themeasured time is within a second range of times.

Example 12

The surgical instrument of Example 9 through Example 11, wherein thecontrol circuit is configured to determine a lockout condition and stopthe motor.

Example 13

A method of controlling motor velocity in a surgical instrument, thesurgical instrument comprising a displacement member configured totranslate within the surgical instrument over a plurality of predefinedzones, a motor coupled to the displacement member to translate thedisplacement member, a control circuit coupled to the motor, a positionsensor coupled to the control circuit, the position sensor configured tomonitor the position of the displacement member, a timer circuit coupledto the control circuit, the timer/counter circuit configured to measureelapsed time, the method comprising: receiving, from a position sensor,a position of a displacement member within a current zone defined by aset displacement interval; measuring, by a timer circuit, a time at aset position of the displacement member, wherein the time is defined bythe time taken by the displacement member to traverse the displacementinterval; and setting, by the control circuit, a command velocity of thedisplacement member for a subsequent zone based on the measured time inthe current zone.

Example 14

The method of Example 13, further comprising: determining, by thecontrol circuit and the timer circuit, the set displacement interval inwhich the displacement member is located, wherein the set displacementinterval is defined by a beginning position and an ending position; andmeasuring, by the control circuit, the time when the displacement memberreaches the ending position of the displacement interval.

Example 15

The method of Example 13 through Example 14, further comprising:comparing, by the control circuit, the measured time to a predeterminedtime stored in a memory coupled to the control circuit; and determining,by the control circuit, whether to adjust or maintain the commandvelocity based on the comparison.

Example 16

The method of Example 15, further comprising maintaining, by the controlcircuit, the command velocity for the subsequent zone the same as thecommand velocity of the current zone when the measured time is within arange of predetermined times.

Example 17

The method of Example 15 through Example 16, further comprising setting,by the control circuit, the command velocity for the subsequent zonedifferent from the command velocity of the current zone when themeasured time is outside a range of predetermined times.

Example 18

The method of Example 17, further comprising skipping, by the controlcircuit, a time measurement for a subsequent zone when the commandvelocity is adjusted.

Example 19

The method of Example 13 through Example 18, further comprisingdefining, by the control circuit, multiple zones are defined for astaple cartridge configured to operate with the surgical instrument.

Example 20

The method of Example 19, further comprising defining, by the controlcircuit, at least two zones having a different length.

Closed Loop Feedback Control of Motor Velocity of a Surgical Staplingand Cutting Instrument Based on Measured Displacement Distance TraveledOver a Specified Time Interval

During use of a motorized surgical stapling and cutting instrument it ispossible that the velocity of the cutting member or the firing membermay need to be measured and adjusted to compensate for tissueconditions. In thick tissue the velocity may be decreased to lower theforce to fire experienced by the cutting member or firing member if theforce to fire experienced by the cutting member or firing member isgreater than a threshold force. In thin tissue the velocity may beincreased if the force to fire experienced by the cutting member orfiring member is less than a threshold. Therefore, it may be desirableto provide a closed loop feedback system that measures and adjusts thevelocity of the cutting member or firing member based on a measurementof distance traveled over a specified time increment. It may bedesirable to measure the velocity of the cutting member or firing memberby measuring distance at fixed set time intervals.

The disclosure now turns to a closed loop feedback system to providevelocity control of a displacement member. The closed loop feedbacksystem adjusts the velocity of the displacement member based on ameasurement of time over a specified distance or displacement of thedisplacement member. In one aspect, the closed loop feedback systemcomprises two phases. A start phase defined as the start of a firingstroke followed by a dynamic firing phase as the I-beam 2514 advancesdistally during the firing stroke. FIGS. 30A and 30B show the I-beam2514 positioned at the start phase of the firing stroke. FIG. 30Aillustrates an end effector 2502 comprising a firing member 2520 coupledto an I-beam 2514 comprising a cutting edge 2509. The anvil 2516 is inthe closed position and the I-beam 2514 is located in a proximal orparked position 9502 at the bottom of the closure ramp 9506. The parkedposition 9502 is the position of the I-beam 2514 prior to traveling upthe anvil 2516 closure ramp 9506 to the top of the ramp 9506 an into theT-slot 9508 and perhaps a distance beyond over a predetermined fixedinitial time interval T₀, which is a fixed time period over which thedisplacement of the displacement member is measured. A top pin 9580 isconfigured to engage a T-slot 9508 and a lockout pin 9582 is configuredto engage a latch feature 9584.

In FIG. 30B the I-beam 2514 is located in a distal position 9504 at theend of time interval T₀ with the top pin 2580 engaged in the T-slot 9508and the bottom pin. As shown in FIGS. 30A-30B, in traveling from theparked position 9502 to the distal position 9504 during the timeinterval T₀, the I-beam 2514 travels a distance indicated as actualmeasured displacement δ₀ in the horizontal distal direction. During thestart phase, the velocity of the I-beam 2514 is set to a predeterminedinitial velocity V₀. A control circuit 2510 measures the actualdisplacement δ₀ traveled by the I-beam 2514 over a predetermined fixedtime interval T₀ from the parked position 9502 to the distal position9504 at the initial velocity V₀. In one aspect, at an initial commandvelocity V₀ of 12 mm/s, the actual measured horizontal displacement δ₀of the I-beam 2512 over a fixed time interval T₀=0.8 sec may be δ₀=10.16mm due to external influences acting on the cutting edge 2509 of theI-beam 2514. As described in more detail below, the time interval T₀ isfixed and the actual displacement of the I-beam 2514 over the fixed timeinterval T₀ is measured and is used to set the command velocity of theI-beam 2514 to slow, medium, or fast in subsequent staple cartridgezones Z₁, Z₂, Z₃ . . . Z_(n) as the I-beam 2514 advances distally. Thenumber of zones may depend on the length/size of the staple cartridge(e.g., 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, >60 mm). The zonesZ₁-Z_(n) are defined in terms of fixed time intervals T₁-T_(n) duringwhich the control circuit 2510 measures the actual displacement of thedisplacement member.

The command velocity or set velocity is the velocity of the motor 2504that is applied to the motor 2504 by the control circuit 2510 and themotor control 2508 in order effect a desired velocity of the I-beam2514. The actual velocity of the I-beam 2514 is determined by thecontrol circuit 2510 by measuring the position of the I-beam 2514 withthe position sensor 2534 at fixed time intervals T_(n) determined by thetimer/counter 2531. In accordance with one aspect of the presentdisclosure, the closed loop feedback control system of the surgicalinstrument measures the actual displacement δ_(n) of the I-beam 2514, ora displacement member, over a predetermined time fixed interval T_(n).Each zone Z_(n) may be defined by a predetermined fixed time intervalT_(n) during which the control circuit 2510 measures the actualdisplacement δ_(n) of the displacement member, e.g., the I-beam 2514.

FIG. 31 illustrates the I-beam 2514 firing stroke illustrated by a chart9509 aligned with the end effector 2502 according to one aspect of thisdisclosure. As shown, the initial zone Z₀, or base zone, is the lengthof a fixed time interval T₀ during which the I-beam 2514 travels fromthe parked position 9502 to a distal position 9504, which may vary basedon external influences acting on the I-beam 2514, such as tissuethickness. The initial time interval T₀ is a set fixed time that theI-beam 2514 is enabled to travel up the closure ramp 9506 and to thedistal position 9504 an initial set velocity V₀. The actual displacementδ₀ of the I-beam 2514 in zone Z₀ during the fixed period T₀ is used toset the command velocity in subsequent zone Z₁.

With reference now to FIGS. 14-15, and 30A-31, at the start phase, e.g.,at the beginning of a firing stroke, the control circuit 2510 isconfigured to initiate firing the displacement member, such as theI-beam 2514, at a predetermined velocity V₀ (e.g., 12 mm/s). During thestart phase, the control circuit 2510 is configured to monitor theposition of the I-beam 2514 and measure the actual displacement δ₀ ofthe I-beam 2514 over a fixed time interval T₀ from the parked position9502, or at the end of a low power mode of operation. The actualdisplacement δ₀ of the displacement member over the fixed time intervalT₀ is used by the control circuit 2510 to determine the firing velocityof the I-beam 2514 through the first zone Z₁. For example, in oneaspect, if the actual displacement is δ₀>10.0 mm the velocity may be setto fast and if the actual displacement is δ₀ 10.0 mm the velocity may beset to medium. Faster or slower time intervals T_(n) may be selectedbased on the length of the staple cartridge 2518. In various aspects, ifa lockout condition is encountered, the motor 2504 will stall before theI-beam 2514 reaches the end of the initial time interval T₀. When thiscondition occurs, the display of the surgical instrument indicates theinstrument status and may issue a stall warning. The display also mayindicate a speed selection.

During the dynamic firing phase, the surgical instrument employs dynamicfiring control of the displacement member, where the control circuit2510 is configured to monitor the position of the I-beam 2514 andmeasure the actual displacement δ_(n) of the I-beam 2514 during the timeinterval T_(n), e.g., from the beginning of a zone to the end of a zone,where the time interval T_(n) may be 0.4 sec or 0.8 sec, for example. InFIG. 31, δ₁ represents the actual displacement of the I-beam 2514 fromthe beginning of zone Z₁ to the end of zone Z₁. Likewise, δ₂ representsthe distance traveled by the I-beam 2514 from the beginning of zone Z₂to the end of zone Z₂, and so on. Table 1 shows zones that may bedefined for staple cartridges 2518 of various sizes.

TABLE 1 Defined Zones For Staple Cartridges Of Various Sizes StapleZones Cartridge Z₁ Z₂ Z₃ Z₄ Z₅ Z₆   35 mm 0-0.4 sec 0.4-0.8 sec 0.8-1.2sec  >1.2 sec N/A N/A 40-45 mm 0-0.4 sec 0.4-0.8 sec 0.8-1.2 sec 1.2-1.6sec  >1.6 sec N/A 55-60 mm 0-0.4 sec 0.4-0.8 sec 0.8-1.2 sec 1.2-1.6 sec1.6-2.0 sec >2.0 sec

For staple cartridges 2518 over 60 mm, the pattern continues, but duringthe last 10-15 mm continues at a command or indicated velocity of theprevious zone pending other interventions for end of stroke, amongothers. At the end of each zone Z_(n), the actual displacement δ_(n) ofthe I-beam 2514 is compared to the values stored in a lookup table(e.g., as shown in Tables 2-5 below) to determine how to set the commandvelocity V_(n+1) for the next zone Z_(n+1). The command velocity isupdated for the next zone and the process continues. Whenever thecommand velocity is updated in zone Z_(n), the next zone Z_(n+1) willnot be evaluated over the time interval T_(n). The end of stroke ishandled in accordance with a predetermined protocol/algorithm of thesurgical instrument including limit switches, controlled deceleration,etc. At the end of stroke, the I-beam 2514 is returned to the initialI-beam park position 9502 at the fast speed. End of return stroke(returning to the parked position 9502) is handled in accordance withthe protocol/algorithm of the surgical instrument. Other zones may bedefined without limitation.

TABLE 2 Distance Traveled Through Zones At Specified Command VelocityFor Various Dynamic Firing Zones Distance (mm) Traveled Through Zone atSpecified Command Velocity Dynamic Firing Zone (sec) Slow Medium FastFirst Zone (T₁ sec long) δ < δ₁ δ₁ < δ < δ₂ δ > δ₂ Intermediate Zones(T₂ sec long) δ < δ₃ δ₃ < δ < δ₄ δ > δ₄ Last Measured Zone (T₃ sec long)δ < δ₅ δ₅ < δ < δ₆ δ > δ₆

TABLE 3 Non-limiting Examples Of Distance Traveled Through Zones AtSpecified Command Velocity For Various Dynamic Firing Zones Distance(mm) Traveled Through Zone at Specified Command Velocity Dynamic FiringZone (sec) Slow Medium Fast First Zone (0.4 sec long) δ < 4 4 < δ < 5δ > 5 Intermediate Zones (0.8 sec long) δ < 8  8 < δ < 10  δ > 10 LastMeasured Zone (0.8 sec long) δ < 7 7 < δ < 9 δ > 9

TABLE 4 Algorithm To Set Velocity Based On Distance Traveled Over FixedTime Interval Algorithm δ_(a) δ_(b) If distance (mm) traveled by I-beamover δ > δ₁ δ ≤ δ₁ fixed time interval is . . . Then initial velocity ofI-beam in T-slot V₁ (mm/sec) V₂ (mm/sec) is . . . And automatic velocityis set at . . . FAST MEDIUM

TABLE 5 Non-limiting Example Of Algorithm To Set Velocity Based OnDistance Traveled Over Fixed Time Interval Algorithm δ_(a) δ₂ Ifdistance (mm) traveled by I-beam over δ > 10 mm δ ≤ 10 mm fixed timeinterval is . . . Then initial velocity of I-beam in T-slot 30 mm/sec 12mm/sec is . . . And automatic velocity is set at . . . FAST MEDIUM

In one aspect, Tables 1-5 may be stored in memory of the surgicalinstrument. The Tables 1-5 may be stored in memory in the form of alook-up table (LUT) such that the control circuit 2510 can retrieve thevalues and control the command velocity of the I-beam 2514 in each zonebased on the values stored in the LUT.

FIG. 32 is a graphical depiction 9600 comparing tissue thickness as afunction of set time interval T_(n) of I-beam stroke 9202 (top graph),force to fire as a function of set time interval T_(n) of I-beam stroke9604 (second graph from the top), dynamic time checks as a function ofset time interval T_(n) of I-beam stroke 9606 (third graph from thetop), and set velocity of I-beam as a function of set time intervalT_(n) of I-beam stroke 9608 (bottom graph) according to one aspect ofthis disclosure. The horizontal axis 9610 for each of the graphs 9602,9604, 9606, 9608 represents set time interval T_(n) of an I-beam 2514stroke for a 60 mm staple cartridge, for example. Staple cartridges ofdifferent lengths can readily be substituted. With reference also toTable 1, the horizontal axis 9610 has been marked to identify thedefined zones Z₁-Z₆ for a 60 mm staple cartridge. As indicated in Table1, the defined zones may be marked for staple cartridges of varioussizes. With reference also to FIG. 14, in accordance with the presentdisclosure, the control circuit 2510 samples the displacement of theI-beam 2514 at set time intervals received form the timer/countercircuit 2531 as the I-beam 2514 advances distally along the staplecartridge 2518 during the firing stroke. At the set time intervals, thecontrol circuit 2510 samples the position of the I-beam 2514 from theposition sensor 2534 and determines the actual displacement δ_(n) of theI-beam 2514 during the time interval T_(n). In this manner, the controlcircuit 2510 can determine the actual velocity of the I-beam 2514 andcompare the actual velocity to the estimated velocity and make anynecessary adjustments to the motor 2504 velocity.

The tissue thickness graph 9602 shows a tissue thickness profile 9620along the staple cartridge 2518 and an indicated thickness in tissueregion 9621 as shown by the horizontal dashed line. The force to firegraph 9604 shows the force to fire profile 9628 along the staplecartridge 2518. The force to fire 9630 remains relatively constant whilethe tissue thickness in tissue region 9622 remains below the indicatedthickness in tissue region 9621 as the I-beam 2514 traverse zones Z₁ andZ₂. As the I-beam 2514 enters zone Z₃, the tissue thickness in tissueregion 9624 increases and the force to fire also increase while theI-beam 2514 traverses the thicker tissue in times zones Z₃, Z₄, and Z₅.As the I-beam 2514 exits zone Z₅ and enters zone Z₆, the tissuethickness 9226 decrease and the force to fire 9234 also decreases.

With reference now to FIGS. 14, 31-32 and Tables 2-3, the velocity V₁ inzone Z₁ is set to the velocity V₀ determined by the control circuit 2510in zone Z₀, which is based on the displacement δ₀ of the I-beam 2514during the initial set time interval T₀ as discussed in reference toFIGS. 30A, 30B. Turning also to the graphs 9606, 9608 in FIG. 32, theinitial set velocity V₀ was set to Medium and thus the set velocity V₁in zone Z₁ is set to Medium such that V₁=V₀.

At set time t₁ (e.g., 0.4 sec for a 60 mm staple cartridge), as theI-beam 2514 exits zone Z₁ and enters zone Z₂, the control circuit 2510measures the actual displacement δ₁ of the I-beam 2514 over the set timeinterval T₁ (0.4 sec long) and determines the actual velocity of theI-beam 2514. With reference to graphs 9606 and 9608 in FIG. 32, at settime t₁, the actual displacement δ₁ of the I-beam 2514 over the set timeinterval T₁ is δ₁=4.5 mm. According to Table 3, an actual displacementof 4.5 mm in zone Z₁ requires the command or set velocity V₂ in zone Z₂to be set to Medium. Accordingly, the control circuit 2510 does notreset the command velocity for zone Z₂ and maintains it at Medium.

At set time t₂ (e.g., 0.8 sec for a 60 mm staple cartridge), as theI-beam 2514 exits zone Z₂ and enters zone Z₃, the control circuit 2510measures the actual displacement δ₂ of the I-beam 2514 over the set timeinterval T₂ (0.8 sec long) and determines the actual velocity of theI-beam 2514. With reference to graphs 9606 and 9608 in FIG. 32, at settime t₂, the actual displacement δ₂ of the I-beam 2514 over the set timeinterval T₂ is δ₂=9.0 mm. According to Table 3, an actual displacementof 9.0 mm in zone Z₂ requires the command or set velocity V₃ in zone Z₃to be set to Medium. Accordingly, the control circuit 2510 does notreset the command velocity for zone Z₃ and maintains it at Medium.

At set time t₃ (e.g., 2.0 sec for a 60 mm staple cartridge), as theI-beam 2514 exits zone Z₃ and enters zone Z₄, the control circuit 2510measures the actual displacement δ₃ of the I-beam 2514 over the set timeinterval T₃ (0.8 sec long) and determines the actual velocity of theI-beam 2514. With reference to graphs 9606 and 9608 in FIG. 32, at settime t₃, the actual displacement δ₃ of the I-beam 2514 over the set timeinterval T₃ is δ₃=7.5 mm. According to Table 3, an actual displacementof 7.5 mm in zone Z₃ requires the command or set velocity V₄ in zone Z₄to be set to Slow. This is because the actual displacement of 7.5 mm isless than 8.0 mm and is outside the previous range. Accordingly, thecontrol circuit 2510 determines that the actual I-beam 2514 velocity inzone Z₃ was slower than expected due to external influences such asthicker tissue than expected as shown in tissue region 9624 in graph9602. Accordingly, the control circuit 2510 resets the command velocityV₄ in zone Z₄ from Medium to Slow.

In one aspect, the control circuit 2510 may be configured to disablevelocity reset in a zone following a zone in which the velocity wasreset. Stated otherwise, whenever the velocity is updated in a presentzone the subsequent zone will not be evaluated. Since the velocity wasupdated in zone Z₄, the distance traveled by the I-beam will not bemeasured at the end of zone Z₄ at set time t₄ (e.g., 2.8 sec for a 60 mmstaple cartridge). Accordingly, the velocity in zone Z₅ will remain thesame as the velocity in zone Z₄ and dynamic displacement measurementsresume at set time t₅ (e.g., 3.6 sec for a 60 mm staple cartridge).

At set time t₅, as the I-beam 2514 exits zone Z₅ and enters zone Z₆, thecontrol circuit 2510 measures the actual displacement δ₅ of the I-beam2514 over the set time interval T₅ (0.8 sec long) and determines theactual velocity of the I-beam 2514. With reference to graphs 9606 and9608 in FIG. 32, at set time t₅, the actual displacement δ₅ of theI-beam 2514 over the set time interval T₅ is δ₅=9.5 mm. According toTable 3, an actual displacement of 9.5 mm in zone Z₅ requires thecommand or set velocity V₆ in zone Z₆ to be set to High. This is becausethe actual displacement of 9.5 mm is greater than 9.0 mm and is outsidethe previous range, the control circuit 2510 determines that the actualvelocity of the I-beam 2514 in zone Z₅ was faster than expected due toexternal influences such as thinner tissue than expected as shown intissue region 9626 in graph 9602. Accordingly, the control circuit 2510resets the command velocity V₆ in zone Z₆ from Slow to High.

FIG. 33 is a graphical depiction 9700 of force to fire as a function oftime comparing slow, medium and fast I-beam 2514 displacement velocitiesaccording to one aspect of this disclosure. The horizontal axis 9702represents time t (sec) that it takes an I-beam to traverse a staplecartridge. The vertical axis 9704 represents force to fire F (N). Thegraphical depiction shows three separate force to fire curves versustime. A first force to fire curve 9712 represents an I-beam 2514 (FIG.14) traversing through thin tissue 9706 at a fast velocity and reachinga maximum force to fire F₁ at the top of the ramp 9506 (FIG. 30B) at t₁.In one example, a fast traverse velocity for the I-beam 2514 is ˜30mm/sec. A second force to fire curve 9714 represents an I-beam 2514traversing through medium tissue 9708 at a medium velocity and reachinga maximum force to fire F₂ at the top of the ramp 9506 at t₂, which isgreater than t₁. In one example, a medium traverse velocity for theI-beam 2514 is ˜12 mm/sec. A third force to fire curve 9716 representsan I-beam 2514 traversing through thick tissue 9710 at a slow velocityand reaching a maximum force to fire F₃ at the top of the ramp 9706 att₃, which is greater than t₂. In one example, a slow traverse velocityfor the I-beam 2514 is ˜9 mm/sec.

FIG. 34 is a logic flow diagram of a process 9800 depicting a controlprogram or logic configuration for controlling command velocity in aninitial firing stage according to one aspect of this disclosure. Withreference also to FIGS. 14 and 30A-34, the control circuit 2510determines 9802 the reference position of the displacement member, suchas the I-beam 2514, for example, based on position information providedby the position sensor 2534. In the I-beam 2514 example, the referenceposition is the proximal or parked position 9502 at the bottom of theclosure ramp 9506 as shown in FIG. 30B. Once the reference position hasbeen determined 9802, the control circuit 2510 and motor control 2508set the command velocity of the motor 2504 to a predetermined commandvelocity V₀ and initiates 9804 firing the displacement member (e.g.,I-beam 2514) at the predetermined command velocity V₀ for the initial orbase zone Z₀. In one example, the initial predetermined command velocityV₀ is ˜12 mm/sec, however, other initial predetermined command velocityV₀ may be employed. The control circuit 2510 monitors 9806 the positionof the displacement member with position information received from theposition sensor 2534 over a predetermined time interval T₀ and recordsthe actual displacement δ₀ of the displacement member at the end of thetime interval T₀ as shown in FIG. 30B. The predetermined displacement X₀is the expected displacement of the displacement member traveling at thecurrent set command velocity V₀. The deviation between actualdisplacement δ₀ and the predetermined displacement X₀ is due at least inpart to external influences acting on the displacement member such astissue thickness acting on the cutting edge 2509 of the I-beam 2514.

With timing information received from the timer/counter circuit 2531 andposition information received from the position sensor 2534, the controlcircuit 2510 measures 9808 the actual displacement δ₀ of the of thedisplacement member over the time interval T₀. Based on the actualdisplacement δ₀ and set time interval T₀ the control circuit 210 sets9810 the command velocity V₁ for the first zone Z₁. As indicated inTable 1, various zones may be defined for staple cartridges of varioussizes. Other zones, however, may be defined. The control circuit 2510sets 9810 the command velocity V₁ for the first zone Z₁ by comparing9812 the actual displacement δ₀ to values stored in memory, such as, forexample, stored in a lookup table (LUT). In one example, as indicated inTable 4 generally and in Table 5 by way of specific example, if theactual displacement δ₀ traveled by the displacement member over thefixed time interval T₀ (sec) of 0.8 sec is greater than 10 mm, then thecommand velocity for the first zone Z₁ is set 9814 to FAST (e.g., 30mm/sec). Otherwise, if the actual displacement δ₀ of the displacementmember over the fixed time interval T₀ (sec) of 0.8 sec is less than orequal to 10 mm, then the command velocity for the first zone Z₁ is set9816 to MEDIUM (e.g., 12 mm/sec). Subsequently, the control circuit 2510checks 9818 for lockout and stops 9820 the motor 2504 if there is alockout condition. Otherwise, the control circuit enters 9822 thedynamic firing phase as described below in reference to process 9850 inFIG. 35.

FIG. 35 is a logic flow diagram of a process 9850 depicting a controlprogram or logic configuration for controlling command velocity in adynamic firing stage according to one aspect of this disclosure. Withreference also to FIGS. 14 and 30A-34, the control circuit 2510 sets9852 the initial command velocity V₁ of the motor 2504 for the firstzone Z₁ based on the displacement δ₀ of the displacement member over theinitial set time interval T₀, as described in reference to the process9800 in FIG. 34. As the displacement member traverses the staplecartridge 2518, the control circuit 2510 receives the position of thedisplacement member from the position sensor 2534 and timing informationfrom the timer/counter 2531 and monitors 9854 the position of thedisplacement member in a zone Z_(n) over the predefined set timeinterval T_(n). At the end of the zone Z_(n), the control circuit 2510measures 9856 the actual displacement δ_(n) of the displacement memberover the predefined time interval T_(n) as the displacement member 2514traverses from the beginning of the zone Z_(n) to the end of the zoneZ_(n) and compares 9858 the actual displacement δ_(n) to a predetermineddisplacement X_(n) for a particular zone as shown generally in Table 2and by way of specific example in Table 3. The predetermineddisplacement X_(n) is the expected displacement of the displacementmember traveling at the current set command velocity V_(n). Thedeviation between actual displacement δ_(n) and the predetermineddisplacement X_(n) is due at least in part to external influences actingon the displacement member such as tissue thickness acting on thecutting edge 2509 of the I-beam 2514.

For example, with reference to Table 3, the distance traveled by thedisplacement member through a zone at a specified command velocity overa set time interval T_(n) is provided for various dynamic firing zones.For example, if the dynamic firing zone is Z₁ (T₁=0.4 sec long) and theactual displacement δ_(n)<4 mm, the command velocity for the next zoneZ₂ is set to FAST; if the actual displacement 4<δ_(n)<5 mm, the commandvelocity for the next zone Z₂ is set to MEDIUM; and if the actualdisplacement δ_(n)>5 mm, the command velocity for the next zone Z₂ isset to SLOW.

If, however, the dynamic firing zone is an intermediate zone Z₂-Z₅(T=0.8 sec long), for example, located between the first zone Z₁ and thelast zone Z₆ and if the actual displacement δ_(n)<8 mm, the commandvelocity for the next zone Z₂ is set to FAST; if the actual displacementκ<δ_(n)<10 mm, the command velocity for the next zone Z₃-Z₅ is set toMEDIUM; and if the actual displacement δ_(n)>10 mm, the command velocityfor the next zone Z₃-Z₅ is set to SLOW.

Finally, if the dynamic firing zone is the last measured zone Z₅ (T=0.8sec long) and the actual displacement δ_(n)<7 mm, the command velocityfor the final zone Z₆ is set to FAST; if the actual displacement7<δ_(n)<9 mm, the command velocity for the final zone Z₆ is set toMEDIUM; and if the actual displacement δ_(n)>9 mm, the command velocityfor the final zone Z₆ is set to SLOW. Other parameters may be employednot only to define the dynamic firing zones but also to define the timeto travel through a zone at specified command velocity for variousdynamic firing zones.

Based on the results of the comparison 9858 algorithm, the controlcircuit 2510 will continue the process 9850. For example, if the resultsof the comparison 9858 indicate that the actual velocity (FAST, MEDIUM,SLOW) in the previous zone Z_(n) is the same as the previous commandvelocity V₁ (FAST, MEDIUM, SLOW), the control circuit 2510 maintains9860 the command velocity for the next zone Z_(n+1) the same as the asthe previous command velocity. The process 9850 continues to monitor9854 the position of the displacement member over the next predefinedzone Z_(n+1). At the end of the next zone Z_(n+1), the control circuit2510 measures 9856 the actual displacement δ_(n+1) of the displacementmember over the predefined time interval T_(n+1) while traversing fromthe beginning of the next zone Z_(n+1) to the end of the next zoneZ_(n1) and compares 9858 the actual displacement δ_(n+1) to apredetermined displacement X_(n+1) for a particular zone as showngenerally in Table 2 and by way of specific example in Table 3. If thereare no changes required to the command velocity, the process 9850 untilthe displacement member, e.g., the I-beam 2514, reaches the end ofstroke 9866 and returns 9868 the displacement member to the referenceposition 9502.

If the results of the comparison 9858 indicate that the actual velocity(FAST, MEDIUM, SLOW) in the previous zone Z_(n) is different as theprevious command velocity V₁ (FAST, MEDIUM, SLOW), the control circuit2510 resets 9862 or updates the command velocity to V_(new) for the nextzone Z_(n+1) according to the algorithm summarized in Tables 2 and 3. Ifthe command speed is rest reset 9862 or updated, the control circuit2510 maintains 9864 the command velocity V_(new) for an additional zoneZ_(n+2). In other words, at the end of the next zone Z_(n+1), thecontrol circuit 2510 does not evaluate or measure the displacement. Theprocess 9850 continues to monitor 9854 the position of the displacementmember over the next predefined zone Z_(n+1) until the displacementmember, e.g., the I-beam 2514, reaches the end of stroke 9866 andreturns 9868 the displacement member to the reference position 9502.

Various aspects of the subject matter described herein are set out inthe following numbered examples:

Example 1

A surgical instrument, comprising: a displacement member configured totranslate within the surgical instrument over a plurality of predefinedzones; a motor coupled to the displacement member to translate thedisplacement member; a control circuit coupled to the motor; a positionsensor coupled to the control circuit, the position sensor configured tomonitor a position of the displacement member; a timer circuit coupledto the control circuit, the timer circuit configured to measure elapsedtime; wherein the control circuit is configured to: receive, from theposition sensor, a position of the displacement member in a current zoneduring a set time interval; measure displacement of the displacementmember at a set time at the end of the set time interval, wherein themeasured displacement is defined as the distance traveled by thedisplacement member during the set time interval at a set commandvelocity for the current zone; and set a command velocity of thedisplacement member for a subsequent zone based on the measureddisplacement of the displacement member within the current zone.

Example 2

The surgical instrument of Example 1, wherein the control circuit isconfigured to: determine the set time interval in which the displacementmember is located, wherein the set time interval is defined by abeginning time and an ending time; and measure the displacement of thedisplacement member at the ending time of the set time interval.

Example 3

The surgical instrument of Example 1 through Example 2, wherein thecontrol circuit is configured to: compare the measured displacement to apredetermined displacement stored in a memory coupled to the controlcircuit; and determine whether to adjust or maintain the commandvelocity for the current zone based on the comparison.

Example 4

The surgical instrument of Example 3, wherein the control circuit isconfigured to set the command velocity for the subsequent zone equal tothe command velocity of the current zone when the measured displacementis within a range of predetermined displacements.

Example 5

The surgical instrument of Example 3 through Example 4, wherein thecontrol circuit is configured to set the command velocity for thesubsequent zone different from the command velocity of the current zonewhen the measured displacement is outside a range of predetermineddisplacements.

Example 6

The surgical instrument of Example 5, wherein the control circuit isconfigured to skip a displacement measurement for a subsequent zone whenthe command velocity is adjusted.

Example 7

The surgical instrument of Example 1 through Example 6, wherein multiplezones are defined for a staple cartridge configured to operate with thesurgical instrument.

Example 8

The surgical instrument of Example 7, wherein at least two zones havedifferent lengths.

Example 9

A surgical instrument, comprising: a displacement member configured totranslate within the surgical instrument over a plurality of predefinedzones; a motor coupled to the displacement member to translate thedisplacement member; a control circuit coupled to the motor; a positionsensor coupled to the control circuit, the position sensor configured tomonitor a position of the displacement member; a timer circuit coupledto the control circuit, the timer/counter circuit configured to measureelapsed time; wherein the control circuit is configured to: receive,from the position sensor, a position of the displacement member in acurrent zone during an initial set time interval; measure displacementof the displacement member from a parked position to a distal positionduring the initial set time interval; and set a command velocity of thedisplacement member for a first dynamic zone based on the measureddisplacement from the parked position to the distal position.

Example 10

The surgical instrument of Example 9, wherein the control circuit isconfigured to compare the measured displacement to a predetermineddisplacement stored in a memory coupled to the control circuit.

Example 11

The surgical instrument of Example 10, wherein the control circuit isconfigured to set the command velocity for the initial zone to a firstvelocity when the measured displacement is within a first range ofdisplacements and set the command velocity for the initial zone to asecond velocity when the measured time is within a second range ofdisplacements.

Example 12

The surgical instrument of Example 9 through Example 11, wherein thecontrol circuit is configured to determine a lockout condition and stopthe motor.

Example 13

A method of controlling motor velocity in a surgical instrument, thesurgical instrument comprising a displacement member configured totranslate within the surgical instrument over a plurality of predefinedzones, a motor coupled to the displacement member to translate thedisplacement member, a control circuit coupled to the motor, a positionsensor coupled to the control circuit, the position sensor configured tomonitor the position of the displacement member, a timer circuit coupledto the control circuit, the timer circuit configured to measure elapsedtime, the method comprising: receiving, by a position sensor, a positionof a displacement member within a current predefined zone defined by apredetermined distance; measuring, by the control circuit, displacementof the displacement member at a set time at the end of the set timeinterval, wherein the measured displacement is defined as the distancetraveled by the displacement member during the set time interval at aset command velocity for the current zone; and setting, by the controlcircuit, a command velocity of the displacement member for a subsequentzone based on the measured displacement within the current zone.

Example 14

The method of Example 13, further comprising: determining, by thecontrol circuit and the timer circuit, the set time interval in whichthe displacement member is located, wherein the set time interval isdefined by a beginning time and an ending time; measuring, by the timercircuit, the displacement of the displacement member at the ending timeof the set time interval.

Example 15

The method of Example 13 through Example 14, further comprising:comparing, by the control circuit, the measured displacement to apredetermined displacement stored in a memory coupled to the controlcircuit; and determining, by the control circuit, whether to adjust ormaintain the command velocity for the current zone based on thecomparison.

Example 16

The method of Example 15, further comprising setting, by the controlcircuit, the command velocity for the subsequent zone equal to thecommand velocity of the current zone when the measured displacement iswithin a range of predetermined displacements.

Example 17

The method of Example 15 through Example 16, further comprising setting,by the control circuit, the command velocity for the subsequent zonedifferent from the command velocity of the current zone when themeasured displacement is outside a range of predetermined displacements.

Example 18

The method of Example 17, further comprising skipping, by the controlcircuit, a displacement measurement for a subsequent zone when thecommand velocity is adjusted.

Example 19

The method of Example 13 through Example 18, further comprisingdefining, by the control circuit, multiple predefined zones for a staplecartridge configured to operate with the surgical instrument.

Example 20

The method of Example 19, further comprising defining, by the controlcircuit, at least two predefined zones having different lengths.

Closed Loop Feedback Control of Motor Velocity of a Surgical Staplingand Cutting Instrument Based on Measured Time Over a Specified Number ofShaft Rotations

During use of a motorized surgical stapling and cutting instrument it ispossible that the velocity of the cutting member or the firing membermay need to be measured and adjusted to compensate for tissueconditions. In thick tissue the velocity may be decreased to lower theforce to fire experienced by the cutting member or firing member if theforce to fire experienced by the cutting member or firing member isgreater than a threshold force. In thin tissue the velocity may beincreased if the force to fire experienced by the cutting member orfiring member is less than a threshold. Therefore, it may be desirableto provide a closed loop feedback system that measures and adjusts thevelocity of the cutting member or firing member based on a measurementof time over a specified number of shaft rotations. It may be desirableto measure the number of shaft rotations at a fixed time.

The disclosure now turns to a closed loop feedback system to providevelocity control of a displacement member. The closed loop feedbacksystem adjusts the velocity of the displacement member based on ameasurement of actual time over a specified number of shaft rotations.In one aspect, the closed loop feedback system comprises two phases. Astart phase defined as the start of a firing stroke followed by adynamic firing phase while the I-beam 2514 advances distally during thefiring stroke. FIGS. 36A and 36B show the I-beam 2514 positioned at thestart phase of the firing stroke. FIG. 36A illustrates an end effector2502 comprising a firing member 2520 coupled to an I-beam 2514comprising a cutting edge 2509. The anvil 2516 is in the closed positionand the I-beam 2514 is located in a proximal or parked position 10002 atthe bottom of the closure ramp 10006. The parked position 10002 is theposition of the I-beam 2514 prior to traveling up the anvil 2516 closureramp 10006 to the top of the ramp 10006 to the T-slot 10008 after apredetermined number of shaft rotations. A top pin 10080 is configuredto engage a T-slot 10008 and a lockout pin 10082 is configured to engagea latch feature 10084.

In FIG. 36B the I-beam 2514 is located in a target position 10004 at thetop of the ramp 10006 with the top pin 10080 engaged in the T-slot10008. As shown in FIGS. 14, 36A, and 36B and, in traveling from theparked position 10002 to the target position 10004, the I-beam 2514travels a distance indicated as X₀ in the horizontal distal directionafter a predetermined number of shaft rotations. During the start phase,the velocity of the I-beam 2514 is set to a predetermined initialvelocity ϕ₀ rotations per seconds. A control circuit 2510 measures theactual time t₀ that it takes the I-beam 2514 to travel up the ramp 10006from the parked position 10002 to the target position 10004 at theinitial velocity ϕ₀ rotations per second. In one aspect, the horizontaldistance is in the range of 5 mm to 10 mm and in one example is 7.4 mmand the initial velocity ϕ₀=5 rotations per second. As described in moredetail below, the actual time t₀ is used to set the command velocity ofthe I-beam 2514 in terms of rotations per second of the shaft to slow,medium, or fast in the subsequent staple cartridge zone Z as the I-beam2514 advances distally. The number of zones may depend on thelength/size of the staple cartridge (e.g., 35 mm, 40 mm, 45 mm, 50 mm,55 mm, 60 mm, >60 mm). The command velocity or set velocity is thevelocity of the motor 2504 that is applied to the motor 2504 by thecontrol circuit 2510 and motor control 2508 in order effect a desiredvelocity of the I-beam 2514. In one aspect, the velocity is determinedbased on rotations of the shaft of the motor 2504 in terms of rotationsper second. The actual velocity of the I-beam 2514 is determined by thecontrol circuit 2510 by measuring the actual time t₀ with thetimer/counter 2531 circuit that it takes the I-beam 2514 to traverse aspecified or fixed distance provided by the position sensor 2534 basedon a set rotation interval assuming, in one example, of 60 threads perinch. In accordance with one aspect of the present disclosure, theclosed loop feedback control system of the surgical instrument measuresthe actual time t_(n) it takes the I-beam 2514, or a displacementmember, to travel a predetermined fixed distance or rotation intervalX_(n) after a predetermined set of rotation interval of the motor shaftassuming a 60 threads per inch. A predetermined fixed distance orrotation interval X_(n) is defined for each zone (e.g., Z₁, Z₂, Z₃ . . .Z_(n)).

FIG. 37 illustrates a screw drive system 10470 that may be employed withthe surgical instrument 10 (FIG. 1) according to one aspect of thisdisclosure. In one aspect, the longitudinally movable drive member 120(FIG. 2) may be replaced with the screw drive (sometime referred to as anut drive) system 10470. The screw drive system 10470 comprises aleadscrew 10472, ball screw or other mechanical linear actuator, adaptedand configured to couple to the shaft 10474 of the motor 82 (FIG. 2) viathe drive gear 10478 to translate rotational motion to linear motion.The leadscrew 10472 is coupled to the firing member 220 via a nut 1476.The firing member 220 is coupled to firing bar 172, which is coupled tothe I-beam 178 as shown and described with reference to FIGS. 2-4. Thedrive gear 10478, which is driven by the shaft 1474 of the motor 82 isadapted to rotate the screw drive system 10470.

The screw drive system 10470 comprises a leadscrew 10472 and a nut10476, also known as a power screw or translation screw, and is adaptedto couple to the shaft 10474 of the motor 82 via the drive gear 10478 totranslate turning motion of the shaft 10474 of the motor 82 into linearmotion of the displacement member, such as the I-beam 2514, for example,which is coupled to the nut 10476. The leadscrew 10472 threads are insliding contact with their counterparts within the nut 10476 such thatas the leadscrew 10472 rotates the nut 10476 translates forward andbackward according to the rotation of the drive gear 10478 as indicated.A ball screw also may be used for low friction application. In a ballscrew, a threaded shaft provides a helical raceway for ball bearingswhich act as a precision screw. As well as being able to apply orwithstand high thrust loads, they can do so with minimum internalfriction. Close tolerances make it suitable for use in high precisionapplications. The ball assembly acts as the nut while the threaded shaftis the screw. The screw drive system 10470, such as the leadscrew 10472and nut 10476, or ball screw drive, may include a threaded shaft having60 threads per inch such that a 60 mm staple cartridge can be traversedin approximately 142 rotations of the motor shaft. For example, onerotation of the threaded shaft of the leadscrew 10472 advances the nut10476 and the displacement member 1 inch (25.4 mm). A 60 mm cartridge is2.36 inches long and requires ˜142 rotations of the leadscrew 10472 toadvance the nut 10476 and the displacement member the full 60 mm strokeif the re is a 1:1 ratio between the rotation of the shaft 10474 and therotation of the leadscrew 10472. Other ratios using gear reductionassemblies may be adapted without limitation. The rotation of the shaft10474 can be measured by a position sensor arrangement comprising one ormore magnets and one or more Hall effect sensors to measure the rotationof the shaft 104747 and provide the shaft rotation signals to thecontrol circuit.

In one aspect, with reference to FIG. 37 and also FIGS. 2-4 and 10-12,the rotations of the shaft 10474 of the motor 82 (FIG. 2) or 1116 (FIG.10) can be measured by measuring the rotation of the shaft 1214 (FIG.11) coupled to the drive gear 86 (FIG. 2) using the absolute positioningsystem 1100 (FIGS. 10 and 12) and position sensor 1200 (FIGS. 11, 12).With reference to FIG. 12, the position sensor 1200 for the absolutepositioning system 1100 comprising a magnetic rotary absolutepositioning system can be employed to measure magnetic rotary positionof the shaft of the motor. The position sensor 1200 is interfaced withthe controller 1104 to provide an absolute positioning system 1100.Additional details of absolute positioning system 1100 and positionsensor 1200 are described above in reference to FIG. 12 and forexpedience will not be repeated here.

Turning now to FIG. 38, there is illustrated an I-beam 2514 firingstroke as a chart 9009 aligned with the end effector 2502 according toone aspect of this disclosure. As shown, the initial zone (Z₀), or basezone, is defined as the distance traveled by the I-beam 2514 from theparked position 10002 to the target position 10004. The measured time T₀is the time it takes the I-beam 2514 to travel up the closure ramp 10006to the target position 10004 at an initial set velocity ϕ₀rotations/sec. The measured times T₁-T₅ are reference periods of timefor traversing the corresponding zones Z₁-Z₅, respectively. Thedisplacement of the I-beam 2514 in zone Z₀ is Θ₀ rotations. The periodT₀, the time it takes for the I-beam 2514 to travel over a distance Θ₀,is used to set the command velocity in the subsequent zone Z₁.

With reference now to FIGS. 14-15, and 36A-38, at the start phase, e.g.,at the beginning of a firing stroke, the control circuit 2510 isconfigured to initiate firing the displacement member, such as theI-beam 2514, at a predetermined velocity ϕ₀ (e.g., 5 rotations/sec).During the start phase, the control circuit 2510 is configured tomonitor the position of the I-beam 2514 and measure the time t₀ (sec) ittakes for the I-beam 2514 to travel from the I-beam 2514 parked position10002 to the I-beam 2514 target position 10004, either to the top of theanvil 2516 closure ramp 10006, or at the end of a low power mode ofoperation. Time t₀ in the initial zone 10010 is used by the controlcircuit 2510 to determine the firing velocity of the I-beam 2514 throughthe first zone Z₁. For example, in one aspect, if time t₀ is <0.9 secthe velocity ϕ₁ may be set to fast and if time t₀≥0.9 sec the velocityϕ₁ may be set to medium. Faster or slower times may be selected based onthe length of the staple cartridge 2518. The actual time t₁-t₅ that ittakes the I-beam 2514 to traverse a corresponding zone Z₁ to Z₅ ismeasured at a corresponding set rotation displacement δ₁-δ₅ and iscompared to a corresponding reference time period T₁-T₅. In variousaspects, if a lockout condition is encountered, the motor 2504 willstall before the I-beam 2514 reaches the target position 10004. Whenthis condition occurs, the surgical instrument display indicates theinstrument status and may issue a stall warning. The display also mayindicate a speed selection.

During the dynamic firing phase, the surgical instrument enters thedynamic firing phase, where the control circuit 2510 is configured tomonitor the rotation interval δ_(n) of the I-beam 2514 and measure thetime t_(n) that it takes the I-beam 2514 to travel from the beginning ofa zone to the end of a zone (e.g., a total distance of 12 rotations or23 rotations). In FIG. 37, the reference time T₁ is the time taken bythe I-beam 2514 to travel from the beginning of zone Z₁ to the end ofzone Z₁ at a set velocity ϕ₁. Likewise, the reference time T₂ is thetime it takes the I-beam 2514 to travel from the beginning of zone Z₂ tothe end of zone Z₂ at a set velocity ϕ₂, and so on. Table 1 shows zonesthat may be defined for staple cartridges 2518 of various sizes.

TABLE 1 Defined Zones For Staple Cartridges Of Various Sizes ZonesStaple Cartridge Z₁ Z₂ Z₃ Z₄ Z₅ Z₆   35 mm 0-12 12-35 35-59 >59 N/A N/Arotations rotations rotations rotations 40-45 mm 0-12 12-35 35-5959-82 >82 N/A rotations rotations rotations rotations rotations 55-60 mm0-12 12-35 35-59 59-82 82-106 >106 rotations rotations rotationsrotations rotations rotations

For staple cartridges 2518 over 60 mm, the pattern continues, but thelast 10-15 mm continues at a command or indicated velocity of theprevious zone pending other interventions for end of stroke, amongothers. At the end of each zone, the actual time t_(n) it took theI-beam 2514 to pass through the zone is compared to the values in othertables (e.g., Tables 2-5 below) to determine how to set the commandvelocity for the next zone. The command velocity is updated for the nextzone and the process continues. Whenever the command velocity isupdated, the next zone will not be evaluated. The end of stroke ishandled in accordance with a predetermined protocol/algorithm of thesurgical instrument including limit switches, controlled deceleration,etc. At the end of stroke, the I-beam 2514 is returned to the initialI-beam park position 10002 at the fast speed. End of return stroke(returning to the parked position 10002) is handled in accordance withthe protocol/algorithm of the surgical instrument. Other zones may bedefined without limitation.

TABLE 2 Time To Travel Through Zones At Specified Command Velocity ForVarious Dynamic Firing Zones Time (sec) to Travel Through Zone atSpecified Command Velocity Dynamic Firing Zone (rotations) Fast MediumSlow First Zone (Θ₁ rotations) t < t₁ t₁ < t < t₂ t > t₂ IntermediateZones (Θ₂ rotations) t < t₃ t₃ < t < t₄ t > t₄ Last Measured Zone (Θ₃rotations) t < t₅ t₅ < t < t₆ t > t₆

TABLE 3 Non-limiting Examples Of Time To Travel Through Zones AtSpecified Command Velocity For Various Dynamic Firing Zones Time (sec)to Travel Through Zone at Specified Command Velocity Dynamic Firing Zone(rotations) Fast Medium Slow First Zone (5 mm long) t < 0.5 0.5 < t <0.6 t > 0.6 Intermediate Zones (10 mm long) t < 0.9 0.9 < t < 1.1 t >1.1 Last Measured Zone (10 mm long) t < 1.0 1.0 < t < 1.3 t > 1.3

TABLE 4 Algorithm To Set Velocity Based On Time To Travel Up RampAlgorithm t_(a) (sec) t_(b) (sec) If time t (sec) for I-beam to travelt₁ < t < t₂ t > t₂ to t₃ up ramp is . . . Then initial velocity V ofI-beam in V₁ (mm/sec) V₂ (mm/sec) T-slot is . . . And automatic velocityis set at . . . FAST MEDIUM

TABLE 5 Non-limiting Example Of Algorithm To Set Velocity Based On TimeTo Travel Up Ramp Algorithm t_(a) (sec) t_(b) (sec) If time t (sec) forI-beam to travel up ramp is . . . t < 0.9 t ≥ 0.9 Then initial velocityof I-beam in T-slot is . . . 30 mm/sec 12 mm/sec And automatic velocityis set at . . . FAST MEDIUM

In one aspect, Tables 1-5 may be stored in memory of the surgicalinstrument. The Tables 1-5 may be stored in memory in the form of alook-up table (LUT) such that the control circuit 2510 can retrieve thevalues and control the command velocity of the I-beam 2514 in each zonebased on the values stored in the LUT.

FIG. 39 is a graphical depiction 10100 comparing the I-beam 2514 strokerotation interval δ_(n) as a function of time 10102 (top graph) andexpected force-to-fire the I-beam 2514 as a function of time 10104(bottom graph) according to one aspect of this disclosure. Referring tothe top graph 10102, the horizontal axis 10106 represents time (t) inseconds (sec) from 0-1.00×, where X is a scaling factor. For example, inone aspect, X=6 and the horizontal axis 10106 represents time from 0-6sec. The vertical axis 10108 represents displacement (δ) of the I-beam2514 in millimeters (mm). The rotation interval δ₁ represents the I-beam2615 stroke 10114 or displacement at the top of the ramp 10006 (FIGS.36A, 36B) for thin tissue and medium thick tissue. The time for theI-beam 2514 to reach the top of ramp stroke 10114 for thin tissue is t₁and the time for the I-beam 2514 to reach the top of ramp stroke 10114for medium thick tissue is t₂. As shown, t₁<t₂, such that it takes lesstime for the I-beam 2514 to reach the top of the ramp stroke 10114 forthin tissue as it takes for medium or thick tissue. In one example, thetop of ramp stroke 10114 rotation interval δ₁ is about 4.1 mm (01.60inches) and the time t₁ is less than 0.9 sec (t₁<0.9 sec) and the timet₂ is greater than 0.9 sec but less than 1.8 sec (0.9<t₂<1.8 sec).Accordingly, with reference also to Table 5, the velocity to reach thetop of ramp stroke 10114 is fast for thin tissue and medium for mediumthick tissue.

Turning now to the bottom graph 10104, the horizontal axis 10110represents time (t) in seconds (sec) and has the same scale of thehorizontal axis 10106 of the top graph 10102. The vertical axis 10112,however, represents expected force to fire (F) the I-beam 2514 innewtons (N) for thin tissue force to fire graph 10116 and medium thicktissue force to fire graph 10118. The thin tissue force to fire graph10116 is lower than medium thick tissue force to fire graph 10118. Thepeak force F₁ for the thin tissue force to fire graph 10116 is lowerthan the peak force F₂ for the medium thick tissue to fire graph 10118.Also, with reference to the top and bottom graphs 10102, 10104, theinitial velocity of the I-beam 2514 in zone Z₀ can be determined basedon estimated tissue thickness. As shown by the thin tissue force to firegraph 10116, the I-beam 2514 reaches the peak force F₁ top of rampstroke 10114 at a fast initial velocity (e.g., 30 mm/sec) and as shownby the medium thick tissue force to fire graph 10118, the I-beam 2514reaches the peak force F₂ top of ramp stroke 10114 at a medium initialvelocity (e.g., 12 mm/sec). Once the initial velocity in zone Z₀ isdetermined, the control circuit 2510 can set the estimated velocity ofthe I-beam 2514 in zone Z₁, and so on.

FIG. 40 is a graphical depiction 10200 comparing tissue thickness as afunction of set rotation interval of I-beam stroke 10202 (top graph),force to fire as a function of set rotation interval of I-beam stroke10204 (second graph from the top), dynamic time checks as a function ofset rotation interval of I-beam stroke 10206 (third graph from the top),and set velocity of I-beam as a function of set rotation interval ofI-beam stroke 10208 (bottom graph) according to one aspect of thisdisclosure. The horizontal axis 10210 for each of the graphs 10202,10204, 10206, 10208 represents set rotation interval of the shaft of themotor 2504 for a 60 mm staple cartridge, for example. The motor 2504shaft rotations correspond to a displacement of the displacement member,such as the I-beam 2514, for example. In one example, a 60 mm cartridge2518 can be traversed by the I-beam 2514 in about 142 rotations of themotor 2504 shaft with a 60 threads per inch screw drive. With referencealso to Table 1, the horizontal axis 10210 has been marked to identifythe defined zones Z₁-Z₆ for a 60 mm staple cartridge. As indicated inTable 1, the defined zones may be marked for staple cartridges ofvarious sizes. The horizontal axis 10210 is marked from 0 to 142rotations for a 60 mm cartridge and 60 threads per inch leadscrew drive.With reference also to FIG. 14, in accordance with the presentdisclosure, the control circuit 2510 samples or measures the elapsedtime from the timer/counter circuit 2531 for a number of motor 2504shaft rotation intervals corresponding to the displacement of the I-beam2514 traversing the staple cartridge 2518 during the firing stroke. Atset rotation intervals δ_(n), 12 rotations, 23 rotations, or othersuitable number of shaft rotations for example, received from theposition sensor 2534, the control circuit 2510 samples or measures theelapsed time t_(n) taken by the I-beam 2514 to travel a distancecorresponding to the fixed rotation intervals δ_(n). For example, aleadscrew with 60 threads per inch corresponds to 0.42 mm per rotation.Thus, 12 rotations of the motor 2504 shaft correspond to a lineardisplacement of 5.04 mm (˜5 mm) and 23 rotations of the motor 2504 shaftcorresponds to a displacement of 9.66 mm (˜10 mm), for example. In thismanner, the control circuit 2510 can determine the actual velocity ofthe I-beam 2514 and compare the actual velocity to the estimatedvelocity and make any necessary adjustments to the motor 2504 velocity.

The tissue thickness graph 10202 shows a tissue thickness profile 10220along the staple cartridge 2518 and an indicated thickness 10221 asshown by the horizontal dashed line. The force to fire graph 10204 showsthe force to fire profile 10228 along the staple cartridge 2518. Theforce to fire 10230 remains relatively constant while the tissuethickness 10222 remains below the indicated thickness 10221 as theI-beam 2514 traverse zones Z₁ and Z₂. As the I-beam 2514 enters zone Z₃,the tissue thickness 10224 increases and the force to fire also increasewhile the I-beam 2514 traverses the thicker tissue in zones Z₃, Z₄, andZ₅. As the I-beam 2514 exits zone Z₅ and enters zone Z₆, the tissuethickness 10226 decrease and the force to fire 10234 also decreases.

With reference now to FIGS. 14, 36A-40 and Tables 2-3, the velocity ϕ₁in zone Z₁ is set to the command velocity ϕ₀ in rotations per seconddetermined by the control circuit 2510 in zone Z₀, which is based on thetime it takes the I-beam 2514 to travel to the top of the ramp 10006 inzone Z₀ as discussed in reference to FIGS. 36A, 36B, and 38. Turningalso to the graphs 10206, 10208 in FIG. 39, the initial set velocity ϕ₀was set to Medium and thus the set velocity ϕ₁ in zone Z₁ is set toMedium such that ϕ₁=ϕ₀.

At set rotation position δ₁ (e.g., 12 rotations [5.04 mm] for a 60 mmstaple cartridge and 60 threads per inch leadscrew), as the I-beam 2514exits zone Z₁ and enters zone Z₂, the control circuit 2510 measures theactual time t₁ that it takes the I-beam 2514 to travel a set distanceduring the set rotation interval Θ₁ (12 rotations, 5.04 mm) anddetermines the actual velocity of the I-beam 2514. With reference tographs 10206 and 10208 in FIG. 39, at set rotation position δ₁, theactual time t₁ it takes the I-beam 2514 to travel a set distance duringthe set rotation interval Θ₁ is t₁=0.55 sec. According to Table 3, anactual travel time t₁=0.55 sec in zone Z₁ requires the command or setvelocity ϕ₂ in zone Z₂ to be set to Medium. Accordingly, the controlcircuit 2510 does not reset the command velocity for zone Z₂ andmaintains it at Medium.

At set rotation position δ₂ (e.g., 35 rotations [14.7 mm] for a 60 mmstaple cartridge and 60 threads per inch leadscrew), as the I-beam 2514exits zone Z₂ and enters zone Z₃, the control circuit 2510 measures theactual time t₂ it takes the I-beam 2514 to travel a set distance duringthe set rotation interval Θ₂ (23 rotations, 9.66 mm) and determines theactual velocity of the I-beam 2514. With reference to graphs 10606 and10608 in FIG. 39, at set rotation position δ₂, the actual time t₂ ittakes the I-beam 2514 to travel a set distance during the set rotationinterval Θ₂ is t₂=0.95 sec. According to Table 3, an actual travel timet₂=0.95 sec in zone Z₂ requires the command or set velocity ϕ₃ in zoneZ₃ to be set to Medium. Accordingly, the control circuit 2510 does notreset the command velocity for zone Z₃ and maintains it at Medium.

At set rotation position δ₃ (e.g., 59 rotations [24.78 mm] for a 60 mmstaple cartridge and 60 threads per inch leadscrew), as the I-beam 2514exits zone Z₃ and enters zone Z₄, the control circuit 2510 measures theactual time t₃ it takes the I-beam 2514 to travel a set distance duringthe set rotation interval Θ₃ (23 rotations, 9.66 mm) and determines theactual velocity of the I-beam 2514. With reference to graphs 10606 and10608 in FIG. 39, at set rotation position δ₃, the actual time t₃ ittakes the I-beam 2514 to travel a set distance during the set rotationinterval Θ₃ is t₃=1.30 sec. According to Table 3, an actual travel timet₃=1.30 sec in zone Z₃ requires the command or set velocity ϕ₄ in zoneZ₄ to be set to Slow. This is because the actual travel time of 1.3 secis greater than 1.10 sec and is outside the previous range. Accordingly,the control circuit 2510 determines that the actual I-beam 2514 velocityin zone Z₃ was slower than expected due to external influences such asthicker tissue than expected as shown in tissue region 10224 in graph10202. Accordingly, the control circuit 2510 resets the command velocityϕ₄ in zone Z₄ from Medium to Slow.

In one aspect, the control circuit 2510 may be configured to disablevelocity reset in a zone following a zone in which the velocity wasreset. Stated otherwise, whenever the velocity is updated in a presentzone the subsequent zone will not be evaluated. Since the velocity wasupdated in zone Z₄, the time it takes the I-beam 2514 to traverse zoneZ₄ will not be measured at the end of zone Z₄ at the set rotationdistance δ₄ (e.g., 82 rotations [34.44 mm] for a 60 mm staplecartridge). Accordingly, the velocity in zone Z₅ will remain the same asthe velocity in zone Z₄ and dynamic time measurements resume at setrotation position δ₅ (e.g., 106 rotations [44.52 mm] for a 60 mm staplecartridge and 60 threads per inch leadscrew).

At set rotation position δ₅ (e.g., 106 rotations [44.52 mm] for a 60 mmstaple cartridge and 60 threads per inch leadscrew) as the I-beam 2514exits zone Z₅ and enters zone Z₆, the control circuit 2510 measures theactual time t₅ it takes the I-beam 2514 to travel a set distance duringthe set rotation interval δ₅ (23 rotations, 9.75 mm) and determines theactual velocity of the I-beam 2514. With reference to graphs 10606 and10608 in FIG. 39, at set rotation position δ₅, the actual time t₅ ittakes the I-beam 2514 to travel a set distance during the set rotationinterval Θ₅ is t₅=0.95 sec. According to Table 3, an actual travel timeof t₅=0.95 sec in zone Z₅ requires the command or set velocity ϕ₆ inzone Z₆ to be set to High. This is because the actual travel time of0.95 sec is less than 1.00 sec is outside the previous range.Accordingly, the control circuit 2510 determines that the actualvelocity of the I-beam 2514 in zone Z₅ was faster than expected due toexternal influences such as thinner tissue than expected as shown intissue region 10626 in graph 10602. Accordingly, the control circuit2510 resets the command velocity ϕ₆ in zone Z₆ from Slow to High.

FIG. 41 is a graphical depiction 10300 of force to fire as a function oftime comparing slow, medium and fast I-beam 2514 displacement velocitiesaccording to one aspect of this disclosure. The horizontal axis 10302represents time t (sec) that it takes an I-beam to traverse a staplecartridge. The vertical axis 10304 represents force to fire F (N). Thegraphical depiction shows three separate force to fire curves versustime. A first force to fire curve 10312 represents an I-beam 2514 (FIG.14) traversing through thin tissue 10306 at a fast velocity and reachinga maximum force to fire F₁ at the top of the ramp 10006 (FIG. 36B) att₁. In one example, a fast traverse velocity for the I-beam 2514 is ˜30mm/sec (˜71 rotations/sec). A second force to fire curve 10314represents an I-beam 2514 traversing through medium tissue 10308 at amedium velocity and reaching a maximum force to fire F₂ at the top ofthe ramp 10006 at t₂, which is greater than t₁. In one example, a mediumtraverse velocity for the I-beam 2514 is ˜12 mm/sec (˜29 rotations/sec).A third force to fire curve 10316 represents an I-beam 2514 traversingthrough thick tissue 10310 at a slow velocity and reaching a maximumforce to fire F₃ at the top of the ramp 9006 at t₃, which is greaterthan t₂. In one example, a slow traverse velocity for the I-beam 2514 is˜9 mm/sec (˜21 rotations/sec).

FIG. 42 is a logic flow diagram of a process 10400 depicting a controlprogram or logic configuration for controlling command velocity in aninitial firing stage according to one aspect of this disclosure. Withreference also to FIGS. 14 and 36A-40, the control circuit 2510determines 10402 the reference position of the displacement member, suchas the I-beam 2514, based on the number of rotations of the motor 2504shaft and the number threads per mm or inch of the leadscrew. Asdiscussed previously, a leadscrew having 60 threads per inch advancesthe displacement member 0.42 mm per rotation of the shaft. The positioninformation based on the shaft rotation information is provided by theposition sensor 2534. In the I-beam 2514 example, the reference positionis the proximal or parked position 10002 at the bottom of the closureramp 10006 as shown in FIG. 36B. Once the reference position isdetermined 10402, the control circuit 2510 and motor control 2508 setthe command velocity of the motor 2504 to a predetermined commandvelocity ϕ₀ and initiates 10404 firing the displacement member (e.g.,I-beam 2514) at the predetermined command velocity ϕ₀ for the initial orbase zone Z₀. In one example, the initial predetermined command velocityϕ₀ is ˜12 mm/sec (29 rotations/sec), however, other initialpredetermined command velocity ϕ₀ may be employed. The control circuit2510 monitors 10406 the shaft rotation information received from theposition sensor 2534 until the I-beam 2514 reaches a target position atthe top of the ramp 10006 as shown in FIG. 36B. The predeterminedrotation interval period T₀ is the expected period that the displacementmember will take to travel a predetermined distance while traveling atthe current set command velocity ϕ₀. The deviation between actualrotation period T_(n) and the predetermined rotation period T₀ is due atleast in part to external influences acting on the displacement membersuch as tissue thickness acting on the cutting edge 2509 of the I-beam2514.

With timing information received from the timer/counter circuit 2531 andshaft rotation information received from the position sensor 2534, thecontrol circuit 2510 measures 10408 the time t₀ it takes thedisplacement member to travel from the reference position 10002 to thetarget position 10004 after a specified number of shaft rotations (e.g.,12 or 24 rotations). The control circuit 210 sets 10410 the commandvelocity ϕ₁ for the first zone Z₁ based on the measured time t₀. Asindicated in Table 1, various defined zones may be defined for staplecartridges of various sizes. Other zones, however, may be defined. Thecontrol circuit 2510 sets 10410 the command velocity ϕ₁ for the firstzone Z₁ by comparing 9412 the measured time t₀ to values stored inmemory, such as, for example, stored in a lookup table (LUT). In oneexample, as indicated in Table 4 generally and in Table 5 by way ofspecific example, if the time t₀ it takes the I-beam 2514 to travel upthe ramp 10006 from the reference position 10002 to the target position10004 at 5 rotations/sec is less than 0.9 sec (t₀<0.9 sec), then thecommand velocity for the first zone Z₁ is set 10414 to FAST (e.g., 30mm/sec, 71 rotations/sec). Otherwise, if the time t₀ (sec) for theI-beam 2514 to travel up the ramp 10006 from the reference position10002 to the target position 10004 at 5 rotations/sec is greater than orequal to 0.9 sec (t₀≥0.9), then the command velocity for the first zoneZ₁ is set 10416 to MEDIUM (e.g., 12 mm/sec, 29 rotations/sec).Subsequently, the control circuit 2510 checks 10418 for lockout andstops 10420 the motor 2504 if there is a lockout condition. Otherwise,the control circuit enters 10422 the dynamic firing phase as describedbelow in reference to process 10450 in FIG. 42.

FIG. 43 is a logic flow diagram of a process 10450 depicting a controlprogram or logic configuration for controlling command velocity in adynamic firing stage according to one aspect of this disclosure. Withreference also to FIGS. 14 and 36A-40, the control circuit 2510 sets10452 the initial command velocity of the motor 2504 in rotations persecond for the first zone Z₁ based on the initial time t₀, as describedin reference to the process 10400 in FIG. 41. As the displacement membertraverses the staple cartridge 2518, the control circuit 2510 receivesthe shaft rotation information from the position sensor 2534 and timinginformation from the timer/counter 2531 circuit and monitors 10454 thenumber of shaft rotations that represent the position of thedisplacement member over the predefined zone Z_(n). At the end of thezone Z_(n), the control circuit 2510 measures 10456 the actual timet_(n) the displacement member took to travel from the beginning of thezone Z_(n) to the end of the zone Z_(n) based on a predetermined numberof shaft rotations and compares 10458 the actual time t_(n) to apredetermined time for a particular zone as shown generally in Table 2and by way of specific example in Table 3. The predetermined rotationperiod T_(n) is the expected rotation period of the displacement membertraveling at the current set command velocity ϕ_(n) rotations/sec. Thedeviation between actual rotation period t_(n) and the predeterminedrotation period T_(n) is due at least in part to external influencesacting on the displacement member such as tissue thickness acting on thecutting edge 2509 of the I-beam 2514.

For example, with reference to Table 3 the time to travel through a zoneat a specified command velocity is provided for various dynamic firingzones. For example, if the dynamic firing zone is the zone Z₁ (12rotations) and t_(n)<0.5 sec, the command velocity for the next zone Z₂is set to FAST; if 0.5<t_(n)<0.6 sec, the command velocity for the nextzone Z₂ is set to MEDIUM; and if t_(n)>0.6 sec, the command velocity forthe next zone Z₂ is set to SLOW.

If, however, the dynamic firing zone is an intermediate zone Z₂-Z₅ (24rotations), for example, located between the first zone Z₁ and the lastzone Z₆ and if t_(n)<0.9 sec, the command velocity for the next zone Z₂is set to FAST; if 0.9<t_(n)<1.1 sec, the command velocity for the nextzone Z₃-Z₅ is set to MEDIUM; and if t_(n)>1.1 sec, the command velocityfor the next zone Z₃-Z₅ is set to SLOW.

Finally, if the dynamic firing zone is the last measured zone Z₅ (24rotations) and t_(n)<1.0 sec, the command velocity for the final zone Z₆is set to FAST; if 1.0<t_(n)<1.3 sec, the command velocity for the finalzone Z₆ is set to MEDIUM; and if t_(n)>1.3 sec, the command velocity forthe final zone Z₆ is set to SLOW. Other parameters may be employed notonly to define the dynamic firing zones but also to define the time totravel through a zone at specified command velocity for various dynamicfiring zones.

Based on the results of the comparison 10458 algorithm, the controlcircuit 2510 will continue the process 10450. For example, if theresults of the comparison 10458 indicate that the actual velocity (FAST,MEDIUM, SLOW) in the previous zone Z_(n) is the same as the previouscommand velocity V₁ (FAST, MEDIUM, SLOW), the control circuit 2510maintains 10460 the command velocity for the next zone Z_(n+1) the sameas the as the previous command velocity. The process 10450 continues tomonitor 10454 the number of shaft rotations over the next predefinedzone Z_(n+1). At the end of the next zone Z_(n+1), the control circuit2510 measures 10456 the time t_(n+1) the displacement member took totravel a distance from the beginning of the next zone Z_(n+1) to the endof the next zone Z_(n1) during the predetermined number of shaftrotations and compares 10458 the actual time t_(n+1) to a predeterminedtime for a particular zone as shown generally in Table 2 and by way ofspecific example in Table 3. If there are no changes required to thecommand velocity, the process 10450 until the number of rotationsindicates that the displacement member, e.g., the I-beam 2514, hasreached the end of stroke 10466 and returns 10468 the displacementmember to the reference position 10002.

If the results of the comparison 10458 indicate that the actual velocity(FAST, MEDIUM, SLOW) in the previous zone Z_(n) is different as theprevious command velocity ϕ₁ (FAST, MEDIUM, SLOW), the control circuit2510 resets 10462 or updates the command velocity for the next zoneZ_(n+1) according to the algorithm summarized in Tables 2 and 3. If thecommand speed is reset 10462 or updated to ϕ_(new), the control circuit2510 maintains 10464 the command velocity ϕ_(new) for an additional zoneZ_(n+2). In other words, at the end of the next zone Z_(n+1), thecontrol circuit 2510 does not evaluate or measure the time. The process10450 continues to monitor 10454 the number of shaft rotationsrepresentative of the position of the displacement member over the nextpredefined zone Z_(n+1) until the number of rotations indicates that thedisplacement member, e.g., the I-beam 2514, has reached the end ofstroke 10466 and returns 10468 the displacement member to the referenceposition 10002.

Various aspects of the subject matter described herein are set out inthe following numbered examples:

Example 1

A surgical instrument, comprising: a displacement member configured totranslate within the surgical instrument over a plurality of predefinedzones; a motor comprising a shaft, the motor coupled to the displacementmember to translate the displacement member; a control circuit coupledto the motor; a position sensor coupled to the control circuit, theposition sensor configured to monitor the rotation of the shaft; a timercircuit coupled to the control circuit, the timer/counter circuitconfigured to measure elapsed time; wherein the control circuit isconfigured to: receive, from the position sensor, rotations of the shaftin a current zone defined by a set rotation interval; measure time at aset position of the rotation interval, wherein the measured time isdefined as the time taken by the displacement member to traverse therotation interval based on a predetermined number of shaft rotations;and set a command velocity of the displacement member for a subsequentzone based on the measured time in the current predefined zone.

Example 2

The surgical instrument of Example 1, wherein the control circuit isconfigured to: determine the set rotation interval in which thedisplacement member is located, wherein the set rotation interval isdefined by a number of rotations of the shaft that result in a lineartranslation of the displacement member from a beginning position to anending position; and measure the time when the displacement memberreaches the ending position of the rotation interval.

Example 3

The surgical instrument of Example 1, wherein the control circuit isconfigured to: compare the measured time to a predetermined time storedin a memory coupled to the control circuit; and determine whether toadjust or maintain the command velocity based on the comparison.

Example 4

The surgical instrument of Example 3, wherein the control circuit isconfigured to maintain the command velocity for the subsequent zone thesame as the command velocity of the current zone when the measured timeis within a range of predetermined times.

Example 5

The surgical instrument of Example 3, wherein the control circuit isconfigured to set the command velocity for the subsequent zone differentfrom the command velocity of the current zone when the measured time isoutside a range of predetermined times.

Example 6

The surgical instrument of claim 5, wherein the control circuit isconfigured to skip a time measurement for a subsequent zone when thecommand velocity is adjusted.

Example 7

The surgical instrument of claim 1, wherein multiple zones are definedfor a staple cartridge configured to operate with the surgicalinstrument.

Example 8

The surgical instrument of claim 7, wherein at least two zones have adifferent length.

Example 9

The surgical instrument of claim 1, further comprising a screw drivesystem coupled to the shaft of the motor, the screw drive systemcomprising a lead screw coupled to a nut, wherein the nut is coupled tothe displacement member.

Example 10

A surgical instrument, comprising: a displacement member configured totranslate within the surgical instrument over a plurality of predefinedzones; a motor comprising a shaft, the motor coupled to the displacementmember to translate the displacement member; a control circuit coupledto the motor; a position sensor coupled to the control circuit, theposition sensor configured to monitor the rotation of the shaft; a timercircuit coupled to the control circuit, the timer/counter circuitconfigured to measure elapsed time; wherein the control circuit isconfigured to: receive, from the position sensor, rotations of the shaftin a current zone defined by a predetermined rotation interval; measuretime as the displacement member moves from a parked position to a targetposition based on a predetermined number of shaft rotations; and set acommand velocity of the displacement member for a first dynamic zonebased on the measured time.

Example 11

The surgical instrument of Example 10, wherein the control circuit isconfigured to compare the measured time to a predetermined time storedin a memory coupled to the control circuit.

Example 12

The surgical instrument of Example 11, wherein the control circuit isconfigured to set the command velocity for the initial zone to a firstvelocity when the measured time is within a first range of times and setthe command velocity for the initial zone to a second velocity when themeasured time is within a second range of times.

Example 13

The surgical instrument of Example 10, wherein the control circuit isconfigured to determine a lockout condition and stop the motor.

Example 14

The surgical instrument of Example 10, further comprising a screw drivesystem coupled to the shaft of the motor, the screw drive systemcomprising a lead screw coupled to a nut, wherein the nut is coupled tothe displacement member.

Example 15

A method of controlling motor velocity in a surgical instrument, thesurgical instrument comprising a displacement member configured totranslate within the surgical instrument over a plurality of predefinedzones, a motor comprising a shaft, the motor coupled to the displacementmember to translate the displacement member, a control circuit coupledto the motor, a position sensor coupled to the control circuit, theposition sensor configured to monitor the rotation of the shaft, a timercircuit coupled to the control circuit, the timer/counter circuitconfigured to measure elapsed time, the method comprising: receiving,from a position sensor, rotations of the shaft in a current zone definedby a set rotation interval; measuring, by a timer circuit, a time at aset position of the of the rotation interval, wherein the measured timeis defined by the time taken by the displacement member to traverse therotation interval based on a predetermined number of shaft rotations;and setting, by the control circuit, a command velocity of thedisplacement member for a subsequent zone based on the measured time inthe current zone.

Example 16

The method of Example 15, further comprising: determining, by thecontrol circuit and the timer circuit, the set rotation interval inwhich the displacement member is located, wherein the set rotationinterval is defined by a number of rotations of the shaft that result ina linear translation of the displacement member from a beginningposition to an ending position; and measuring, by the control circuit,the time when the displacement member reaches the ending position of therotation interval.

Example 17

The method of Example 15, further comprising: comparing, by the controlcircuit, the measured time to a predetermined time stored in a memorycoupled to the control circuit; and determining, by the control circuit,whether to adjust or maintain the command velocity based on thecomparison.

Example 18

The method of Example 17, further comprising maintaining, by the controlcircuit, the command velocity for the subsequent zone the same as thecommand velocity of the current zone when the measured time is within arange of predetermined times.

Example 19

The method of Example 17, further comprising setting, by the controlcircuit, the command velocity for the subsequent zone different from thecommand velocity of the current zone when the measured time is outside arange of predetermined times.

Example 20

The method of Example 19, further comprising skipping, by the controlcircuit, a time measurement for a subsequent zone when the commandvelocity is adjusted.

Example 21

The method of Example 15, further comprising defining, by the controlcircuit, multiple zones are defined for a staple cartridge configured tooperate with the surgical instrument.

Example 22

The method of Example 21, further comprising defining, by the controlcircuit, at least two zones having a different length.

Systems and Methods for Controlling Displaying Motor Velocity for aSurgical Instrument

During use of a motorized surgical stapling and cutting instrument it ispossible that the user may not know the command velocity or the actualvelocity of the cutting member or firing member. Therefore, it may bedesirable to communicate information to the user through a displayscreen to provide information about the firing velocity of the cuttingmember or firing member where the velocity is related to the size of thezone that is indicated on the display screen. It may be desirable tocommunicate velocity control to show the command velocity as well as thefiring mode in a closed loop feedback automatic mode or manuallyselected mode.

The disclosure now turns to a closed loop feedback system forcontrolling motor velocity based on a variety of conditions. The closedloop feedback system as executed by the control circuit 2510 can beconfigured to implement either a default, e.g., pre-programmed, firingcondition or a user-selected firing condition. The user selected firingcondition can be selected during the open loop portion or otherwiseprior to the closed loop portion of the displacement stroke. In oneaspect, the user-selected firing condition is configured to override theexecution of the default or pre-programmed firing condition.

Turning now to FIG. 44, there is shown a perspective view of a surgicalinstrument 10500 according to one aspect of this disclosure. In oneaspect, a surgical instrument 10500 comprising an end effector 10504connected via a shaft 10503 to a handle assembly 10502 further comprisesa display 10506. The surgical instrument 10500 comprises a home button10508, an articulation toggle 10510, a firing trigger and safety release10512, and a closure trigger 10514.

In the following discussion, reference should also be made to FIG. 14.The display 10506 is operably coupled to the control circuit 2510 suchthat the control circuit 2510 can cause the display 10506 to showvarious information associated with the operation of the instrument10500, such as information determined by or from the position sensor2534, the current sensor 2536, and/or the other sensors 2538. In oneaspect, the display 10506 can be configured to display the velocity atwhich the I-beam 2514 is set to be translated by the motor 2504, i.e., acommand velocity, and/or the actual velocity at which the I-beam 2514 isbeing translated. The command velocity is the set, target, or desiredvelocity. The command velocity at which the I-beam 2514 is to betranslated can be determined by either receiving the motor set point,which dictates the velocity at which the motor 2504 drives the I-beam2514, dictated by the motor drive signal 2524 from the motor control2508 or storing the motor drive signal 2524 that is provided to themotor control 2508 in a memory for subsequent retrieval. The actualvelocity at which the I-beam 2514, or other component of the firingdrive system, is being translated can be determined by monitoring theposition of the I-beam 2514 over a time period, which can be tracked bythe control circuit 2510 via input from the timer/counter 2531.

In various aspects, the display 10506 of the surgical instrument 10500can be positioned directly on the exterior housing or casing of thehandle assembly 10502 or otherwise integrally associated with thesurgical instrument 10500. In other aspects, the display 10506 can beremovably connectable or attachable to the surgical instrument 10500. Instill other aspects, the display 10506 can be separate or otherwisedistinct from the surgical instrument 10500. The display 10506 can becommunicably coupled to the control circuit 2510 via either a wiredconnection or a wireless connection.

FIG. 45 is a detail view of a display 10506 portion of the surgicalinstrument 10500 shown in FIG. 44 according to one aspect of thisdisclosure. The display 10506 includes an LCD display 10516 tocommunicate velocity control including showing the command velocity aswell as if the firing mode is in a closed loop feedback (automatic) modeor manually selected mode. The display 10506 provides transectionfeedback by displaying a graphic image of an end effector staplecartridge 10518 with a knife 10520 and rows of staples 10522. A leftgraphic label 10524 indicates the distance 10528 the knife 10520 hastraveled (e.g., 10 mm) distally and a right graphic label 10526indicates the velocity of the knife 10520 as it travels distally wherethe current velocity is circled (e.g., 3), where 1 is fast, 2 is medium,and 3 is slow velocity. The velocity may be selected manually orautomatically based on the conditions of the tissue.

FIG. 46 is a logic flow diagram of a process 10550 depicting a controlprogram or logic configuration for controlling a display according toone aspect of this disclosure. Reference should also be made to FIGS. 14and 44. Accordingly, the control circuit 2510 first receives 10552command velocity from the instrument input and sets 10554 the motor 2504velocity to the command velocity. The control circuit 2510 receives10556 position information of the displacement member (e.g., I-beam2514) from the position sensor 2534 and receives 10558 timinginformation from the timer/counter circuit 2531 and determines 10560 thevelocity of the displacement member. The velocity of the I-beam 2514 caninclude the actual velocity at which the I-beam 2514 is translated orthe command velocity at which the I-beam 2514 was set to be translated.The control circuit 2510 then causes the display 10506 to display 10562an indicia indicative of the actual velocity of the displacement memberand/or the command velocity depending on the configuration of theinstrument 10500. In one aspect, the control circuit 2510 determines10560 both the actual and command velocities of the I-beam 2514 and thencauses the display 10506 to display 10562 an indicia for each of theactual and command velocities. The control circuit 2510 then compares10564 the velocity of the displacement member to the command velocityand causes the display 10506 to display 10566 an indicia regarding thecomparison. For example, the control circuit 2510 can cause the display10506 to display indicia that show whether the actual velocity of thedisplacement member is equal to, greater than, or less than the commandvelocity. In some aspects, the control circuit 2510 causes the display10506 to display the actual velocity of the displacement member relativeto a range of command velocities such as, for example, low or slow(e.g., 0-7 mm/sec), medium (e.g., 7-12 mm/sec), or high or fast (e.g.,12-30 mm/sec). Furthermore, the control circuit 2510 receives 10568 theoperation status of the battery from the energy source 2512 such asvoltage, current, impedance, capacity, temperature, and the like, andcauses the display 10506 to display 10570 the status of the battery.

The indicia for the velocity or velocities can include a numeralindicating a velocity presented in, e.g., mm/sec, a numeral indicating avalue of the velocity relative to a maximum or minimum value, a shapethat is altered according to the velocity, a shape that is filled orshaded with a color according to the velocity, a shape or alphanumericcharacter that flashes according to the velocity, a shape oralphanumeric character that changes in color according to the velocity,a dial indicative of the absolute or relative velocity, a shape oralphanumeric character indicative of a zone in which the velocity falls,an icon or series of icons representing an animal indicative of avelocity, various other indicia configured to represent a velocity, andcombinations thereof. These indicia are illustrated and described belowin the form of depictions of display feedback screens in reference toFIGS. 47-81, for example.

FIGS. 47-49 illustrate various displays 10600 depicting a velocityfeedback screen according to one aspect of this disclosure. The display10600 depicts a graphic image of an end effector staple cartridge 10618.The display 10600 comprises velocity indicia 10602 to indicate thecommand or actual velocity of the displacement member (e.g., I-beam2514). In one aspect, the velocity indicia 10602 comprises a shape orseries of shapes that are filled or shaded proportionally to thevelocity, such as is depicted in FIGS. 47-49. The shape or shapes of thevelocity indicia 10602 can include, e.g., a triangular frustum or anyother suitable geometric shape. In one aspect, the velocity indicia10602 can comprise a plurality of zones that are indicative of therelative value of the velocity. In one such aspect, the velocity indicia10602 comprises a first zone 10604, a second zone 10606, and a thirdzone 10608 that correspond respectively to slow, medium, and fastvelocity. The control circuit 2510 causes the display 10600 to indicatethe zone in which the velocity falls, as determined by the controlcircuit 2510 as discussed above. Each of the zones 10604, 10606, 10608may comprise graduations 10610 or marks to provide additional resolutionof the command velocity of the I-beam 2514 element. In addition, thevelocity indicia 10602 may comprise a graphic that represents slowvelocity such as a silhouette of a tortoise 10612 below the first zone10604 and a graphic that represents fast velocity such as a silhouetteof a hare 10614 above the third zone 10608. As illustrated in FIG. 47,the command velocity is set to medium as indicated by the first andsecond zones 10604, 10606 being filled or shaded while the third zone16008 is unfilled or unshaded. As illustrated in FIG. 48, the commandvelocity is set to low as indicated by only the first zone 10604 beingfilled or shaded while the second and third zones 10606, 16008 areunfilled or unshaded. As illustrated in FIG. 49, the command velocity isset to high as indicated by all three zones 10604, 10606, 10608 beingcompletely filled or shaded. A status bar 10620 at the bottom of thedisplay 10600 indicates operation status as normal (e.g., green) orcautionary (e.g., yellow). In the examples shown in FIGS. 47-49 thestatus bar 10620 indicates normal operation.

In some aspects, the display 10600 further comprises a mode indiciaindicative of the mode to which the surgical instrument 10500 is set.Such modes can include, e.g., an automatic mode 10616 or a manual mode10622. Such modes and processes for the control circuit 2510 to controlthe velocity at which the I-beam 2514 is driven and correspondinglycause the display 10600 to indicate the mode of the surgical instrument10500 are described in U.S. patent application Attorney Docket. No.END8270USNP/170191, which is herein incorporated by reference in itsentirety. In some aspects, the automatic mode 10616 or manual mode 10622may be flash 10624.

The velocity indicia 10602 can additionally comprise variousalphanumeric characters configured to indicate the velocity. Thealphanumeric characters can be presented singularly or in combinationwith other indicia, such as the zones.

In one aspect, the size or relative portion of the display 10600occupied by the velocity indicia 10602 corresponds to the velocity. Forexample, the velocity indicia 10602 can be filled or shaded according tothe velocity relative to a maximum velocity, as is depicted in FIGS.47-55. In another aspect wherein the velocity indicia 10602 comprisealphanumeric characters, the size of the alphanumeric character canincrease in size according to the velocity determined by the controlcircuit 2510.

FIGS. 50-52 illustrate various displays 10630 depicting a velocityfeedback screen according to one aspect of this disclosure. The display10630 depicts a graphic image of an end effector staple cartridge 10642.The display 10630 comprises velocity indicia 10632 to indicate thecommand or actual velocity of the displacement member (e.g., I-beam2514). In one aspect, the velocity indicia 10632 comprises a shape orseries of shapes that are filled or shaded proportionally to thevelocity, such as is depicted in FIGS. 50-52. The shape or shapes of thevelocity indicia 10632 can include, e.g., a triangular frustum or anyother suitable geometric shape. In one aspect, the velocity indicia10632 can comprise a plurality of zones that are indicative of therelative value of the velocity. In one such aspect, the velocity indicia10632 comprises a first zone 10634, a second zone 10636, and a thirdzone 10638 that correspond respectively to slow, medium, and fastvelocity. The control circuit 2510 causes the display 10630 to indicatethe zone in which the velocity falls, as determined by the controlcircuit 2510 as discussed above. Each of the zones 10634, 10636, 10638may comprise graduations 10640 or marks to provide additional resolutionof the command velocity of the I-beam 2514 element. In addition, thevelocity indicia 10632 may comprise an alphanumeric character 10644 toindicate either automatic or manual modes of operation. In theillustrated examples, the mode is set to AUTO for automatic. A statusbar 10646 at the bottom of the display 10630 indicates operation statusas normal (e.g., green) or cautionary (e.g., yellow). In the examplesshown in FIGS. 50-52 the status bar 10646 indicates normal operation.

As illustrated in FIG. 50, the command velocity is set to medium asindicated by filled or shaded first and second zones 10634, 10636 andunfilled or unshaded third zone 16038. As illustrated in FIG. 51, thecommand velocity is set to low as indicated by a filled or shaded firstzone 10634 and unfilled or unshaded second and third zones 10636, 16038are unfilled or unshaded. As illustrated in FIG. 52, the commandvelocity is set to high as indicated by all three zones 10634, 10636,10638 filled or shaded.

FIGS. 53-55 illustrate various displays 10650 depicting a velocityfeedback screen according to one aspect of this disclosure. The display10650 depicts a graphic image of an end effector staple cartridge 10662.The display 10650 comprises velocity indicia 10652 to indicate thecommand velocity as well as the actual velocity of the displacementmember (e.g., I-beam 2514). In one aspect, the velocity indicia 10652comprises a shape or series of shapes that are filled or shadedproportionally to the velocity, such as is depicted in FIGS. 53-55. Theshape or shapes of the velocity indicia 10652 can include, e.g., atriangular frustum or any other suitable geometric shape. In one aspect,the velocity indicia 10652 can comprise a plurality of zones that areindicative of the relative value of the velocity. In one such aspect,the velocity indicia 10652 comprises a first zone 10654, a second zone10656, and a third zone 10658 that correspond respectively to slow,medium, and fast actual velocity. The control circuit 2510 causes thedisplay 10650 to indicate the zone in which the velocity falls, asdetermined by the control circuit 2510 as discussed above. Each of thezones 10654, 10656, 10658 may comprise graduations 10660 or marks toprovide additional resolution of the command velocity of the I-beam 2514element. In addition the velocity indicia 10652 may include an iconcomprising an alphanumeric character located within a geometric elementto represent low, medium, and high velocity. In the example illustratedin FIGS. 53-55, the velocity indicia 10652 may include an additionalalphanumeric character such as a circled “H” icon 10653, a circled “M”icon 10655, and a circled “L” icon 10657 indicate the command velocity.Depending on the command velocity, the H″ icon 10653, the “M” icon10655, or the “L” icon 10657 will be filled, shaded, or lit to indicatethe command velocity setting. In addition, the velocity indicia 10652may comprise an alphanumeric character 10664 to indicate eitherautomatic or manual modes of operation. In the illustrated examples, themode is set to MANUAL for automatic. A status bar 10666 at the bottom ofthe display 10650 indicates operation status as normal (e.g., green) orcautionary (e.g., yellow). In the examples shown in FIGS. 53-55 thestatus bar 10666 indicates normal operation. In one aspect, the fill orshade color of the “H” icon 10653, the “M” icon graphic 10655, and the“L” icon 10657 may be same as the fill or shade color of the status bar10666 to indicate normal or caution modes of operation.

As illustrated in FIG. 53, the actual velocity is set to medium asindicated by the filled or shaded first and second zones 10654, 1066 andan unfilled or unshaded third zone 16058 and the command velocity is setto medium as indicated by the filled or shaded “M” icon 10655 (andunfilled or unshaded “H” and “L” icons 10653, 10657). As illustrated inFIG. 54, the actual velocity is slow as indicated by the filled orshaded first zone 10654 (and unfilled or unshaded second and third zones10656, 16058) and the command velocity is set to low as furtherindicated by the filled “L” icon 10657 (and unfilled or unshaded “H” and“M” icons 10653, 10655). As illustrated in FIG. 55, the actual velocityis fast as indicated by all three zones 10654, 10656, 10658 completelyfilled or shaded and as the command velocity is set to high as furtherindicated by the filled or shaded “H” icon 10653 (and unfilled orunshaded circled “M” and circled “L” graphics 10655, 10657).

FIGS. 56-58 illustrate various displays 10670, 10670′ depicting variousvelocity feedback screens according to one aspect of this disclosure.The display 10670, 10670′ depicts a graphic image of an end effectorstaple cartridge 10682. The display 10670, 10670′ comprises velocityindicia 10672, 10672′ to indicate the command velocity as well as theactual velocity of the displacement member (e.g., I-beam 2514) duringthe firing cycle. In one aspect, the velocity indicia 10672, 10672′comprises a shape or series of shapes that are filled or shadedproportionally to the velocity, such as is depicted in FIGS. 56-58. Theshape or shapes of the velocity indicia 10672, 10672′ can include, e.g.,an arcuate or any other suitable geometric shape. In one aspect, thevelocity indicia 10672, 10672′ can comprise an arcuate graphic 10678,10678′ comprising multiple graduations 10680 to indicate the actualvelocity from 0-30 mm/sec, for example, of the displacement member.Alphanumeric characters 10684 (0, 7, 12, and 30) are disposed about theperimeter of the arcuate graphic 10678, 10678′ to indicate the actualvelocity by a filled or shaded region 10686. The display 10670 shown inFIG. 56 is a slightly modified version of the display 10670′ shown inFIGS. 57 and 58. For example, the arcuate graphic 10678 of the display10670 shown in FIG. 62 includes cutouts around the alphanumericcharacters 10684 (7 and 12), for example.

In addition, the velocity indicia 10672, 10672′ further comprises afilled or shaded circle icon 10676 with one or more white arrows toindicate the command velocity, such that, for example, one arrow refersto low velocity or slow, two arrows refer to medium velocity, and threearrows refer to high velocity or fast. An additional alphanumericcharacter 10674 indicates the units of velocity, e.g., mm/sec. As thevelocity increases or decreases, the shaded region 10686 increases anddecreases correspondingly. A status bar 10688 at the bottom of thedisplay 10670 indicates operation status as normal (e.g., green) orcautionary (e.g., yellow). In the examples shown in FIGS. 56-58 thestatus bar 10688 indicates normal operation. In one aspect, the fill orshade color of the velocity region 10686 may be same as the fill orshade color of the status bar 10688 to indicate normal or caution modesof operation.

As illustrated in FIG. 56, the actual velocity is fast (˜12 mm/sec) asindicated by the shaded region 10686 and the command velocity is set tohigh as indicated by the three arrows in the circle icon 10676. As notedearlier, the alphanumeric characters 10684 “7” and “12” include acutout. As illustrated in FIG. 57, the actual velocity also is fast (˜30mm/sec) as indicated by the shaded region 10686 and the command velocityis set to high as indicated by the three arrows in the circle icon10676. As illustrated in FIG. 58, the command velocity is medium (˜10mm/sec) as indicated by the shaded region 10686 and the command velocityis set to medium as indicated by the two arrows in the circle icon10676.

FIGS. 59-61 illustrate various displays 10690, 10690′, 10690″ depictingvarious velocity feedback screens according to one aspect of thisdisclosure. The display 10690, 10690′, 10690″ depicts a graphic image ofan end effector staple cartridge 10702, 10702′, 10702″. The display10690, 10690′, 10690″ comprises velocity indicia 10692, 10692′, 10692″to indicate the command velocity as well as the actual velocity of thedisplacement member (e.g., I-beam 2514) during the firing cycle. In oneaspect, the velocity indicia 10692, 10692′, 10692″ comprises a shape orseries of shapes that are filled or shaded proportionally to thevelocity, such as is depicted in FIGS. 59-61. The shape or shapes of thevelocity indicia 10692, 10692′, 10692″ can include, e.g., an arcuate orany other suitable geometric shape. In one aspect, the velocity indicia10692, 10692′, 10692″ can comprise an arcuate graphic 10698, 10698′,10698″ comprising multiple graduations 10700, 10700′, 10700″ to indicatethe actual velocity from 0-30 mm/sec, for example. Alphanumericcharacters 10704, 10704′, 10704″ (0, 7, 12, and 30) are disposed aboutthe perimeter of the arcuate graphic 10698, 10698′, 10698″ to indicatethe actual velocity by a filled or shaded region 10706, 10706′, 10706″.The displays 10690, 10690′, 10690″ are substantially similar but includesome slight variations. For example, the arcuate graphic 10678 of thedisplay 10690 depicted in FIG. 59 includes cutouts around thealphanumeric characters 10704 (7 and 12), for example, whereas thearcuate graphic 10678′, 10678″ of the displays 10690′, 10690″ depictedin FIGS. 60 and 61 do not. Furthermore, the velocity indicia 10692,10692″ of the displays 10690, 10690″ depicted in FIGS. 59 and 61 includean alphanumeric character 10694, 10694″ to indicate the units ofvelocity, e.g., mm/sec, at a bottom portion of the display 10690, 10690″whereas the display 10690′ depicted in FIG. 60 includes an alphanumericcharacter 10694′ to indicate the units of velocity, e.g., mm/sec, at atop portion of the display 10690′.

In addition, the velocity indicia 10692, 10692′, 10692″ furthercomprises a filled or shaded circle icon 10696, 10696′, 10696″ with oneor more white arrows to indicate the command velocity, such that, forexample, one arrow refers to low velocity or slow, two arrows refer tomedium velocity, and three arrows refer to high velocity or fast. As thevelocity increases or decreases the filled or shaded region 10706,10706′, 10706″ increases and decreases correspondingly. A status bar10708, 10708′, 10708″ at the bottom of the displays 10690, 10690′,10690″ indicates operation status as normal (e.g., green) or cautionary(e.g., yellow). In the example shown in FIG. 59, the status bar 10708indicates caution operation. In the examples shown in FIGS. 60-61, thebars 10708′, 10708″ indicate normal operation. In one aspect, the fillor shade color of the velocity region 10706, 10706′, 10706″ may be sameas the fill or shade color of the status bar 10708, 10708′, 10708″ toindicate normal or caution modes of operation.

As illustrated in FIG. 59, the actual velocity is medium (˜12 mm/sec) asindicated by the shaded region 10706 but the command velocity is set tofast as indicated by the three arrows in the circle icon 10696. As notedearlier, the alphanumeric characters 10704 “7” and “12” include acutout. As illustrated in FIG. 60, the actual velocity is slow (˜7mm/sec) as indicated by the shaded region 10706′ and the commandvelocity is set to low as indicated by the single arrow in the circleicon 10696′. As illustrated in FIG. 61, the actual velocity also is slow(˜2 mm/sec) as indicated by the shaded region 10706″ and the commandvelocity is set to low as indicated by the single arrow in the circleicon 10696″.

FIGS. 62-64 illustrate various displays 10720, 10720′ depicting variousvelocity feedback screens according to one aspect of this disclosure.The display 10720, 10720′ depicts a graphic image of an end effectorstaple cartridge 10732. The display 10720, 10720′ comprises velocityindicia 10722, 10722′ to indicate the command velocity as well as theactual velocity of the displacement member (e.g., I-beam 2514) duringthe firing cycle. In one aspect, the velocity indicia 10722, 10722′comprises a shape or series of shapes that are filled or shadedproportionally to the velocity, such as is depicted in FIGS. 62-64. Theshape or shapes of the velocity indicia 10722, 10722′ can include, e.g.,an arcuate or any other suitable geometric shape. In one aspect, thevelocity indicia 10722, 10722′ can comprise an arcuate graphic 10728,10728′ comprising multiple graduations 10736 to indicate the actualvelocity from 0-30 mm/sec, for example. Alphanumeric characters 10734(0, 7, 12, and 30) are disposed about the perimeter of the arcuategraphic 10728, 10728′ to indicate the actual velocity by a filled orshaded region 10736. The display 10720 shown in FIG. 62 is a slightlymodified version of the display 10720′ shown in FIGS. 63 and 64. Forexample, the arcuate graphic 10728 of the display 10720 shown in FIG. 62includes cutouts around the alphanumeric characters 10734 (7 and 12),for example.

In addition, the velocity indicia 10722, 10722′ further comprises aclear or white circle icon 10726 with one or more black or shaded arrowsto indicate the command velocity, such that, for example, one arrowrefers to low velocity or slow, two arrows refer to medium velocity, andthree arrows refer to high velocity or fast. An additional alphanumericcharacter 10724 indicates the units of velocity, e.g., mm/sec. As thevelocity increases or decreases, the shaded region 10736 increases anddecreases correspondingly. A status bar 10738 at the bottom of thedisplay 10720, 1072′ indicates operation status as normal (e.g., green)or cautionary (e.g., yellow). In the examples shown in FIGS. 62-64 thestatus bar 10738 indicates normal operation. In one aspect, the fill orshade color of the velocity region 10736 be same as the fill or shadecolor of the status bar 10738 to indicate normal or caution modes ofoperation.

As illustrated in FIG. 62, the actual velocity is medium to fast (˜12mm/sec) as indicated by the shaded region 10736 and the command velocityis set to high as indicated by the three arrows in the circle icon10726. As noted earlier, the alphanumeric characters 10734 “7” and “12”include a cutout. As illustrated in FIG. 63, the actual velocity is fast(˜30 mm/sec) as indicated by the shaded region 10736 and the commandvelocity is set to high as indicated by the three arrows in the circleicon 10726. As illustrated in FIG. 64, the actual velocity is medium(˜10 mm/sec) as indicated by the shaded region 10736 and the commandvelocity is set to medium as indicated by the two arrows in the circleicon 10726.

FIGS. 65-67 illustrate various displays 10740, 10740′, 10740″ depictingvarious velocity feedback screens according to one aspect of thisdisclosure. The display 10740, 10740′, 10740″ depicts a graphic image ofan end effector staple cartridge 10752, 10752′, 10752″. The display10740, 10740′, 10740″ comprises velocity indicia 10742, 10742′, 10742″to indicate the command velocity as well as the actual velocity of thedisplacement member (e.g., I-beam 2514) during the firing cycle. In oneaspect, the velocity indicia 10742, 10742′, 10742″ comprises a shape orseries of shapes that are filled or shaded proportionally to thevelocity, such as is depicted in FIGS. 65-67. The shape or shapes of thevelocity indicia 10742, 10742′, 10742″ can include, e.g., an arcuate orany other suitable geometric shape. In one aspect, the velocity indicia10742, 10742′, 10742″ can comprise an arcuate graphic 10748, 10748′,10748″ comprising multiple graduations 10750, 10750′, 10750″ to indicatethe actual velocity from 0-30 mm/sec, for example. Alphanumericcharacters 10704, 10704′, 10704″ (0, 7, 12, and 30) are disposed aboutthe perimeter of the arcuate graphic 10748, 10748′, 10748″ to indicatethe actual velocity by a filled or shaded region 10756, 10756′, 10756″.The displays 10740, 10740′, 10740″ are substantially similar but includesome slight variations. For example, the arcuate graphic 10748 of thedisplay 10740 depicted in FIG. 65 includes cutouts around thealphanumeric characters 10754 (7 and 12), for example, whereas thearcuate graphic 10748′, 10748″ of the displays 10740′, 10740″ depictedin FIGS. 66 and 67 do not. Furthermore, the velocity indicia 10742,10742″ of the displays 10740, 10740″ depicted in FIGS. 65 and 67 includean alphanumeric character 10744, 10744″ to indicate the units ofvelocity, e.g., mm/sec, at a bottom portion of the display 10740, 10740″whereas the display 10740′ depicted in FIG. 66 includes an alphanumericcharacter 10744′ to indicate the units of velocity, e.g., mm/sec, at atop portion of the display 10740′.

In addition, the velocity indicia 10742, 10742′, 10742″ furthercomprises a clear or white circle icon 10746, 10746′, 10746″ with one ormore black or shaded arrows to indicate the command velocity, such that,for example, one arrow refers to low velocity or slow, two arrows referto medium velocity, and three arrows refer to high velocity or fast. Asthe velocity increases or decreases the filled or shaded region 10756,10756′, 10756″ increases and decreases correspondingly. A status bar10758, 10758′, 10758″ at the bottom of the displays 10740, 10740′,10740″ indicates operation status as normal (e.g., green) or cautionary(e.g., yellow). In the example shown in FIG. 65, the status bar 10758indicates caution operation. In the examples shown in FIGS. 66-67, thebars 10758′, 10758″ indicate normal operation. In one aspect, the fillor shade color of the velocity region 10756, 10756′, 10756″ may be sameas the fill or shade color of the status bar 10758, 10758′, 10758″ toindicate normal or caution modes of operation.

As illustrated in FIG. 65, the actual velocity is medium (˜12 mm/sec) asindicated by the shaded region 10756 and the command velocity is set tohigh velocity as indicated by the three arrows in the circle icon 10726.As noted earlier, the alphanumeric characters 10734 “7” and “12” includea cutout. As illustrated in FIG. 66, actual velocity is slow (˜7 mm/sec)as indicated by the shaded region 10756′ and the command velocity is setto low as indicated by the single arrow in the circle icon 10746′. Asillustrated in FIG. 67, the actual velocity is slow (˜2 mm/sec) asindicated by the shaded region 10756″ and the command velocity is set tolow as indicated by the single arrow in the circle icon 10746″.

FIGS. 68-70 illustrate a display 10760 depicting a velocity feedbackscreen according to one aspect of this disclosure. The display 10760depicts a graphic image of an end effector staple cartridge 10772. Thedisplay 10760 comprises velocity indicia 10762 to indicate the commandvelocity as well as the actual velocity of the displacement member(e.g., I-beam 2514). In one aspect, the velocity indicia 10762 comprisesa shape or series of shapes that are filled or shaded proportionally tothe velocity, such as is depicted in FIGS. 68-70. The shape or shapes ofthe velocity indicia 10762 can include, e.g., a rectangular shape or anyother suitable geometric shape. In one aspect, the velocity indicia10762 can comprise a rectangular zone 10778 that is filled or shaded toindicate the value of the actual velocity. The control circuit 2510causes the display 10760 to indicate the zone in which the velocityfalls, as determined by the control circuit 2510 as discussed above. Therectangular zone 10778 may comprise graduations or marks to provideadditional resolution of the command velocity of the I-beam 2514element. In addition the velocity indicia 10762 may include an icon10766 comprising an alphanumeric character located within a geometricelement to represent automatic or manual mode of operation. In theillustrated examples, the mode is set to automatic “A” and the commandvelocity is set to a range of 7 to 12 mm/sec. Thus the automatic icon10766 is located between the range that the actual velocity can verybetween. A filled or shaded region 10770 indicates the range that theactual velocity can very between, e.g., 7-12 mm/sec. A bar graph element10764 indicates the actual velocity of the displacement member. A statusbar 10776 at the bottom of the display 10760 indicates operation statusas normal (e.g., green) or cautionary (e.g., yellow). In the examplesshown in FIGS. 68-70 the status bar 10776 indicates normal operation. Inone aspect, the fill or shade color of the filled or shaded region 10770may be same as the fill or shade color of the status bar 10776 toindicate normal or caution modes of operation. An additionalalphanumeric character 10762 indicates the units of velocity, e.g.,mm/sec. Additional alphanumeric characters 10768 indicate the commandvelocity range (e.g., 0-7, 7-12, 12-30).

As illustrated in FIG. 68, the automatic “A” command velocity icon 10766is located between 7-12 mm/sec and the actual velocity as indicated bythe bar graph element 10764 is located toward the upper end of the setrange. As illustrated in FIG. 69, the actual velocity is located towardthe bottom of the set range of 7-12 mm/sec as indicated by the bar graphelement 10764. As illustrated in FIG. 70, the actual velocity is slow asindicated by the bar graph element 10764 and the automatic range is 0-7mm/sec as indicated by the position of the icon 10766.

FIGS. 71-73 illustrate a display 10780 depicting a velocity feedbackscreen according to one aspect of this disclosure. The display 10780depicts a graphic image of an end effector staple cartridge 10792. Thedisplay 10780 comprises velocity indicia 10782 to indicate the commandvelocity as well as the actual velocity of the displacement member(e.g., I-beam 2514). In one aspect, the velocity indicia 10782 comprisesa shape or series of shapes that are filled or shaded proportionally tothe velocity, such as is depicted in FIGS. 71-73. The shape or shapes ofthe velocity indicia 10782 can include, e.g., a rectangular shape or anyother suitable geometric shape. In one aspect, the velocity indicia10782 can comprise a rectangular element 10798 that is filled or shadedto indicate the value of the actual velocity. The control circuit 2510causes the display 10780 to indicate the zone in which the velocityfalls, as determined by the control circuit 2510 as discussed above. Therectangular element 10798 may comprise graduations or marks to provideadditional resolution of the command velocity of the I-beam 2514element. In addition the velocity indicia 10782 may include an icon10786 comprising an alphanumeric character located within a geometricelement to represent automatic or manual mode of operation. In theillustrated examples, the mode is set to manual “M” and the commandvelocity is set to a range of 7 to 12 mm/sec. The icon 10786 isconnected to a bar 10792 which indicates the mid point of the range onthe rectangular element 10798. Thus the automatic icon 10786 is locatedbetween the range that the actual velocity can very between. A filled orshaded region 10790 indicates the range that the actual velocity canvery between, e.g., 7-12 mm/sec. A bar graph element 10784 indicates theactual velocity of the displacement member. A status bar 10796 at thebottom of the display 10780 indicates operation status as normal (e.g.,green) or cautionary (e.g., yellow). In the examples shown in FIGS.71-72 the status bar 10796 indicates normal operation and as indicatedin FIG. 73, the status bar 10796 indicates the status as cautionary. Inone example, the cautionary status may be set because the actualvelocity as indicated by the bar graph element 10784 is well below theset range of 12-30 mm/sec, which could indicate that the cutting elementencountered thicker tissue than expected. In one aspect, the fill orshade color of the filled or shaded region 10790 may be same as the fillor shade color of the status bar 10796 to indicate normal or cautionmodes of operation. An additional alphanumeric character 10794 indicatesthe units of velocity, e.g., mm/sec. Additional alphanumeric characters10788 indicate the command velocity range (e.g., 0-7, 7-12, 12-30).

As illustrated in FIG. 71, the manual “M” command velocity range icon10786 is located between 7-12 mm/sec and the actual velocity isindicated by the bar graph element 10784 to be between the set rangejust above the bar 10792. As illustrated in FIG. 72, the actual velocityis within the set range of 12-30 mm/sec as indicated by the bar graphelement 10784 and just below the bar 10792. As illustrated in FIG. 73,the actual velocity is located below the set range of 12-30 mm/sec asindicated by the bar graph 10784 and the bar 10792.

FIGS. 74-76 illustrate a display 10800 depicting a velocity feedbackscreen according to one aspect of this disclosure. The display 10800depicts a graphic image of an end effector staple cartridge 10812. Thedisplay 10800 comprises velocity indicia 10802 to indicate the commandvelocity as well as the actual velocity of the displacement member(e.g., I-beam 2514). In one aspect, the velocity indicia 10802 comprisesa shape or series of shapes that are filled or shaded proportionally tothe velocity, such as is depicted in FIGS. 74-76 The shape or shapes ofthe velocity indicia 10802 can include, e.g., a rectangular shape or anyother suitable geometric shape. In one aspect, the velocity indicia10802 can comprise a rectangular element 10814 that is divided into twosmaller rectangular elements 10804, 10806. The bottom element 10804indicates the command or “set” velocity (e.g., 30 mm/sec) and the topelement 10806 indicates the actual velocity (e.g., 25 mm/sec). Anadditional alphanumeric character 10808 indicates the units of velocity,e.g., mm/sec. A status bar 10810 at the bottom of the display 10800indicates operation status as normal (e.g., green) or cautionary (e.g.,yellow). In the examples shown in FIGS. 74-75 the status bar 10810indicates normal operation and as indicated in FIG. 76, the status bar10810 indicates the status as cautionary. In one example, the cautionarystatus may be set because the actual velocity 6 mm/sec as indicated bythe top rectangular element 10806 is well below the set command velocityof 12 mm/sec, which could indicate that the cutting element encounteredthicker tissue than expected.

As illustrated in FIG. 74, the command velocity is set to 30 mm/sec asindicated by the bottom rectangular element 1084 and the actual velocityis 25 mm/sec as indicated by the top rectangular element 10806. Asillustrated in FIG. 75, the command velocity is set to 12 mm/sec asindicated by the bottom rectangular element 1084 and the actual velocityis 11 mm/sec as indicated by the top rectangular element 10806. Asillustrated in FIG. 76, the command velocity is set to 12 mm/sec asindicated by the bottom rectangular element 1084 and the actual velocityis 6 mm/sec as indicated by the top rectangular element 10806.

FIGS. 77-80 illustrate a display 10820 depicting a velocity feedbackscreen according to one aspect of this disclosure. The display 10820depicts a graphic image of an end effector staple cartridge 10832. Thedisplay 10820 comprises velocity indicia 10822 to indicate the commandvelocity as well as the actual velocity of the displacement member(e.g., I-beam 2514). In one aspect, the velocity indicia 10822 comprisesa shape or series of shapes that are filled or shaded proportionally tothe velocity, such as is depicted in FIGS. 77-80. The shape or shapes ofthe velocity indicia 10822 can include, e.g., an arcuate shape or anyother suitable geometric shape. In one aspect, the velocity indicia10822 can comprise an arcuate element 10828 that is divided into threesmaller elements 10836 a, 10836 b, 10836 c. The smaller elements 10836a, 10836 b, 10836 c when filled or shaded represent the command velocityrange. An icon 10826 comprising an alphanumeric element encompassed in ageometric shape represents automatic “A” or manual “M” mode ofoperation. A needle 10840 is connected to the icon 10826 and indicatesthe actual velocity much like a speedometer ad including graduations10830 for increased resolution. As shown in FIG. 77, the first element10836 a is shaded and represents a command velocity between 0-7 mm/sec(low). As shown in FIG. 78, the second element 10836 b is shaded andrepresents a command velocity between 7-12 mm/sec (medium). As shown inFIG. 79, the third element 10836 c is shaded and represents a commandvelocity between 12-30 mm/sec (high). An additional alphanumericcharacter 10824 indicates the units of velocity, e.g., mm/sec. A statusbar 10838 at the bottom of the display 10820 indicates operation statusas normal (e.g., green) or cautionary (e.g., yellow). In the examplesshown in FIGS. 77-79 the status bar 10838 indicates normal operation andas indicated in FIG. 80, the status bar 10838 indicates the status ascautionary. In one example, the cautionary status may be set because theactual velocity as indicated by the needle 10840 is above the commandvelocity range indicated in the first element 10836 a, which couldindicate that the cutting element encountered thinner tissue thanexpected.

As illustrated in FIG. 77, the command velocity is set to a low range of0-7 mm/sec as indicated by the first element 10836 a and the actualvelocity is about 3.5 mm/sec as indicated by the needle 10840. Asillustrated in FIG. 78, the command velocity is set to a medium range of7-12 mm/sec as indicated by the second element 10836 b and the actualvelocity is about 9.5 mm/sec as indicated by the needle 10840. Asillustrated in FIG. 79, the command velocity is set to a high range of12-30 mm/sec as indicated by the third element 10836 c and the actualvelocity is about 21 mm/sec as indicated by the needle 10840. In each ofthe examples illustrated in FIGS. 77-79, the operation is normal and thestatus bar 10838 indicates normal operation. Turning now to FIG. 80, thecommand velocity is set to a low range of 0-7 mm/sec as indicated by thefirst element 10836 a and the actual velocity is about 9.5 mm/sec asindicated by the needle 10840, which is outside the command velocityrange. Accordingly, the status bar 10838 is set to indicate caution. Aspreviously discussed, the cautionary operation is indicated because theactual velocity as indicated by the needle 10840 is higher than theupper limit of the command velocity range indicating perhaps that thecutting element encountered tissue that is thinner than expected.

FIG. 81 illustrates a display 10860 depicting a battery feedback screenaccording to one aspect of this disclosure. The display 10860 depicts agraphic image of a battery 10864 communicating an overheated battery10864. If the battery 10864 is in an overheated state, it may not havethe ability complete the firing as requested indicating an overheatedbattery condition. The display 10860 includes an icon that representsheat 10868 such as the sun, for example. An icon of a thermometer 10866also may indicate the actual temperature of the battery 10864. A cautionicon 10870 and a cautionary status bar 10872 is displayed to indicatethe overheated battery 10864 state.

Various aspects of the subject matter described herein are set out inthe following numbered examples:

Example 1

A surgical instrument comprising: a displacement member configured totranslate within the surgical instrument; a motor coupled to thedisplacement member to translate the displacement member; a display; acontrol circuit coupled to the motor and the display; a position sensorcoupled to the control circuit, the position sensor configured tomonitor a position of the displacement member; and wherein the controlcircuit is configured to: determine a velocity of the displacementmember via the position sensor; cause the display to present a modeindicia that is indicative of a mode of the surgical instrument, whereinthe mode comprises an automatic mode and a manual mode, and cause thedisplay to present an indicia that is indicative of the velocity of thedisplacement member, wherein a portion of the display occupied by theindicia corresponds to the velocity of the displacement member.

Example 2

The surgical instrument of Example 1, wherein the indicia is a firstindicia, the control circuit is further configured to: provide a setpoint velocity to the motor, the motor set point configured to cause themotor to drive the displacement member at a motor velocity; and causethe display to present a second indicia indicative of the motor setpoint velocity.

Example 3

The surgical instrument of Example 1 through Example 2, wherein theindicia comprises a plurality of zones, each of the plurality of zonesindicative of a velocity level.

Example 4

The surgical instrument of Example 3, wherein the plurality of zonescomprise a first zone indicative of a low velocity, a second zoneindicative of a medium velocity, and a third zone indicative of a fastvelocity.

Example 5

A surgical instrument comprising: a displacement member configured totranslate within the surgical instrument; a motor coupled to thedisplacement member to translate the displacement member; a display; acontrol circuit coupled to the motor and the display; a position sensorcoupled to the control circuit, the position sensor configured tomonitor a position of the displacement member; and wherein the controlcircuit is configured to: provide a motor set point to the motor, themotor set point configured to cause the motor to drive the displacementmember at a velocity; display an indicia on the display that isindicative of the velocity of the displacement member, wherein a portionof the display occupied by the indicia corresponds to the velocity ofthe displacement member, and display a second indicia on the displaythat is indicative of the motor set point velocity.

Example 6

The surgical instrument of Example 5, wherein the control circuit isfurther configured to cause the display to present a mode indicia thatis indicative of a mode of the surgical instrument.

Example 7

The surgical instrument of Example 6, wherein the mode comprises anautomatic mode and a manual mode.

Example 8

The surgical instrument of Example 5, wherein the control circuit isfurther configured to: display an image representative of thedisplacement member; and display progress of the image representative ofthe displacement member as the displacement member advances distally.

Example 9

The surgical instrument of Example 5 through Example 8, wherein thecontrol circuit is further configured to cause the display to present asecond indicia indicative of the motor set point velocity, wherein thesecond indicia represents a range of motor set point velocities.

Example 10

The surgical instrument of Example 5 through Example 9, wherein thecontrol circuit is further configured to display a status bar thatrepresents operation status of the surgical instrument.

Example 11

The surgical instrument of Example 10, wherein the status bar representsnormal operation when the velocity of the displacement member is withina range of motor set point velocities.

Example 12

The surgical instrument of Example 10 through Example 11, wherein thestatus bar represents cautionary operation when the velocity of thedisplacement member is outside a range of motor set point velocities.

Example 13

The surgical instrument of Example 5 through Example 12, wherein thecontrol circuit is further configured to: monitor a condition of abattery; and cause the display to present an image of a batteryindicative of the condition of the battery.

Example 14

A method of operating a surgical instrument, the surgical instrumentcomprising a displacement member configured to translate within thesurgical instrument, a motor coupled to the displacement member totranslate the displacement member, a display, a control circuit coupledto the motor and the display, a position sensor coupled to the controlcircuit, the position sensor configured to monitor a position of thedisplacement member, the method comprising: determining, by the controlcircuit, a velocity of the displacement member via the position sensor;and presenting, by the control circuit, an indicia on the display thatis indicative of the velocity of the displacement member, wherein aportion of the display occupied by the indicia corresponds to thevelocity of the displacement member, and wherein the indiciarepresentative of a higher velocity is larger than the indiciarepresentative of a lower velocity.

Example 15

The method of Example 14, wherein the indicia is a first indicia, themethod further comprising: providing, by the control circuit, a setpoint velocity to the motor, the motor set point configured to cause themotor to drive the displacement member at a motor velocity; andpresenting, by the control circuit, a second indicia on the display thatis indicative of the motor set point velocity.

Example 16

The method of Example 14 through Example 15, further comprisingpresenting, by the control circuit, on the display a mode indicia thatis indicative of a mode of the surgical instrument.

Example 17

The method of Example 16, further comprising presenting, by the controlcircuit, on the display a mode comprising an automatic mode and a manualmode.

Example 18

The method of Example 14 through Example 17, further comprisingpresenting, by the control circuit, on the display an indicia comprisinga plurality of zones, each of the plurality of zones indicative of avelocity level.

Example 19

The method of Example 18, further comprising presenting, by the controlcircuit, on the display a plurality of zones comprising a first zoneindicative of a low velocity, a second zone indicative of a mediumvelocity, and a third zone indicative of a fast velocity.

Example 20

The method of claim 14 through Example 19, further comprising:monitoring, by the control circuit, a condition of a battery; andpresenting, by the control circuit, on the display an image of a batteryindicative of the condition of the battery.

Systems and Methods for Controlling Motor Speed According to User Inputfor a Surgical Instrument

During use of a motorized surgical stapling and cutting instrument it ispossible that the user may not know the command velocity or the actualvelocity of the cutting member or firing member. Therefore, it may bedesirable to provide the user the ability to control the firing speedthrough manual selection. It may be desirable to provide a surgicalinstrument with a first firing condition that is set by the surgicalinstrument based on a measure of distance traveled by the cutting memberor the firing member and a time element and a second firing conditionthat is predetermined by the user.

The disclosure now turns to a closed loop feedback system forcontrolling motor velocity based on a variety of conditions. The closedloop feedback system as executed by the control circuit 2510 can beconfigured to implement either a default, e.g., pre-programmed, firingcondition or a user-selected firing condition. The user selected firingcondition can be selected during the open loop portion or otherwiseprior to the closed loop portion of the displacement stroke. In oneaspect, the user-selected firing condition is configured to override theexecution of the default or pre-programmed firing condition.

Turning now to FIG. 82, there is shown a perspective view of a surgicalinstrument 10500 according to one aspect of this disclosure. In oneaspect, a surgical instrument 10500 comprising an end effector 10504connected via a shaft 10503 to a handle assembly 10502 further comprisesa display 10506. The surgical instrument 10500 comprises a home button10508, an articulation toggle 10510, a firing trigger and safety release10512, and a closure trigger 10514.

In the following discussion, reference should also be made to FIG. 14.The display 10506 is operably coupled to the control circuit 2510 suchthat the control circuit 2510 can cause the display 10506 to showvarious information associated with the operation of the instrument10500, such as information determined by or from the position sensor2534, the current sensor 2536, and/or the other sensors 2538. In oneaspect, the display 10506 can be configured to display the velocity atwhich the I-beam 2514 is set to be translated by the motor 2504, i.e., acommand velocity, and/or the actual velocity at which the I-beam 2514 isbeing translated. The command velocity is the set, target, or desiredvelocity. The command velocity at which the I-beam 2514 is to betranslated can be determined by either receiving the motor set point,which dictates the velocity at which the motor 2504 drives the I-beam2514, dictated by the motor drive signal 2524 from the motor control2508 or storing the motor drive signal 2524 that is provided to themotor control 2508 in a memory for subsequent retrieval. The actualvelocity at which the I-beam 2514, or other component of the firingdrive system, is being translated can be determined by monitoring theposition of the I-beam 2514 over a time period, which can be tracked bythe control circuit 2510 via input from the timer/counter 2531.

In various aspects, the display 10506 of the surgical instrument 10500can be positioned directly on the exterior housing or casing of thehandle assembly 10502 or otherwise integrally associated with thesurgical instrument 10500. In other aspects, the display 10506 can beremovably connectable or attachable to the surgical instrument 10500. Instill other aspects, the display 10506 can be separate or otherwisedistinct from the surgical instrument 10500. The display 10506 can becommunicably coupled to the control circuit 2510 via either a wiredconnection or a wireless connection.

FIG. 83 is a detail view of a display 10506 portion of the surgicalinstrument 10500 shown in FIG. 82 according to one aspect of thisdisclosure. The display 10506 includes an LCD display 10516 tocommunicate velocity control including showing the command velocity aswell as if the firing mode is in a closed loop feedback (automatic) modeor manually selected mode. The display 10506 provides transectionfeedback by displaying a graphic image of an end effector staplecartridge 10518 with a knife 10520 and rows of staples 10522. A leftgraphic label 10524 indicates the distance 10528 the knife 10520 hastraveled (e.g., 10 mm) distally and a right graphic label 10526indicates the velocity of the knife 10520 as it travels distally wherethe current velocity is circled (e.g., 3), where 1 is fast, 2 is medium,and 3 is slow velocity. The velocity may be selected manually orautomatically based on the conditions of the tissue.

FIG. 84 is a logic flow diagram of a process 11000 depicting a controlprogram or logic configuration for controlling a display according toone aspect of this disclosure. Reference should also be made to FIGS. 14and 82. The process 11000 depicted in FIG. 82 relates to the capabilityfor a user to select the speed of the firing stroke. To begin theprocess 11000, the control circuit 2510 initiates a firing stroke 11010.The firing stroke is initiated 11010 by translating the displacementmember a first distance. When the displacement member is moved a firstdistance, the control circuit is configured to measure the duration oftime required for the displacement member to translate the firstdistance. The measuring of such translation of the displacement member apredetermined first distance, allows the control circuit to be able tocalculate the thickness of the tissue being, for example, cut and/orstapled by the surgical instrument. Prior to firing by, for example,translating the knife 10520 of FIG. 83 distally through the surgicalinstrument 10500, the user is capable of manually selecting the firingspeed by choosing a velocity selection from a variety of speedsdiscussed in more detail below. Based on the calculation of thethickness of tissue from the first distance and the duration of time,the user may able to only select from a variety of speeds appropriatefor the procedure. In the alternative, the user may be able to manuallychoose a velocity selection from all of the variety of speeds. Afterinitiating the firing stroke 11010, the control circuit 2510 assesseswhether, by a first time, the user has made a velocity selection 11020.If the user has not made a velocity selection 11020, the control circuit2510 is configured to determine the position of the displacement memberat this time 11022. By determining the position of the displacementmember, or knife 10520, the control circuit 2510 can set the motorvelocity accordingly 11024. Thus, in the absence of a user input, thecontrol circuit 2510 automatically sets the motor velocity to carry outthe firing stroke at a corresponding speed. Alternatively, if a userdoes make a velocity selection by a first time 11020, the controlcircuit 2510 is configured to control the motor by setting the motorvelocity to correspond with the user selection 11026. After either theuser manually selects the firing speed or the control circuit 2510automatically sets the firing speed, the process for setting thevelocity of the firing stroke comes to an end 11028, and the surgicalinstrument may continue or begin another function.

FIGS. 85 and 86 depict various displays 11100 depicting a user selectionmenu screen according to one aspect of this disclosure. During asurgical procedure, the information presented on the display 11100 maybe communicated throughout the operating room to additional screens,such as, for example, a primary screen connected to a laparoscopiccamera. The display 11100 depicts a graphic image of an end effectorstaple cartridge 11132. An alphanumeric character 11104 indicates theunits of velocity, e.g., mm/sec. The display 11100 comprises selectionmenu indicia 11102 to indicate the available speeds of the displacementmember (e.g., I-beam 2514) during a firing stroke. In one such aspect,the selection menu indicia 10602 can comprise four menu options 11112,11114, 11116, 11118 in the shape of circles. The shape of the selectionmenu indicia 11102 does not have to be circular, as numerous shapes areenvisioned. The shape or shapes of the selection menu indicia 11102 caninclude, for example, a triangle any other suitable geometric shape. Afirst menu option 11112 is indicative of an automatic mode of thesurgical instrument 10500. The automatic mode is represented in thefirst menu option 11112 by a capitalized letter “A”. The automatic modemay be represented in alternative fashions, including, for example, bythe shortened word “auto” or the lowercase letter “a”. A second menuoption 11114 is indicative of a slow mode of the surgical instrument10500. The slow mode is represented in the second menu option 11114 by asingle arrowhead within a circle. The slow mode may be represented inalternative fashions, such as, for example, by the word “slow” or by anumeric value indicative of the velocity of the displacement memberduring the slow mode. A third menu option 11116 is indicative of amedium mode of the surgical instrument 10500. The medium mode isrepresented in the third menu option 11114 by a double arrowhead withina circle. The medium mode may be represented in alternative fashions,such as, for example, by the word “medium” or by a numeric valueindicative of the velocity of the displacement member during the mediummode. A fourth menu option 11118 is indicative of a fast mode of thesurgical instrument 10500. The fast mode is represented in the fourthmenu option 11118 by a triple arrowhead within a circle. The fast modemay be represented in alternative fashions, such as, for example, by theword “fast” or by a numeric value indicative of the velocity of thedisplacement member during the fast mode. During a firing stroke, astatus bar 11138 at the bottom of the display 11100 indicates operationstatus as normal (e.g., green) or cautionary (e.g., yellow). As thedisplacement member is not yet being translated in FIGS. 85 and 86, thestatus bar 11138 is empty.

FIG. 85 is representative of one embodiment of a display 11100 thatpresents itself for a user to choose the firing speed of a displacementmember. In order to trigger the control circuit 2510 to present thisdisplay 11100, a user may close the jaws of the end effector (e.g. 10504in FIG. 82). Without any user input, the motor 2504 operates in anautomatic mode. In order to switch out of the automatic mode to a manualmode, the surgeon may press a button, such as the articulation toggle10510 illustrated in FIG. 87, for a brief period of time. This briefperiod of time can last, for example, for approximately two seconds.After this brief period of time elapses, the control circuit causes thedisplay to show various information associated with selecting a firingspeed as part of an interactive selection menu depicted in FIG. 85. Forexample, the display can show four menu options relating to the velocitymode: automatic mode; slow mode; medium mode; and fast mode.Additionally, or alternatively, the display 11100 may be a touch screen,wherein the user can simply touch the screen to reach the interactiveselection menu.

When the user selects the automatic mode, the control circuit 2510 cancontrol the output of the motor 2504, and thus, the velocity of theI-beam 2514, or displacement member, in response to various conditions.When the user selects the slow mode, the control circuit 2510 slows thevelocity of the motor 2504. Reducing the output of the motor 2504results in a slower translation of the I-beam 2514, and thus, a slowerfiring speed. When the user selects the fast mode, the control circuit2510 increases the velocity of the motor 2504. Increasing the output ofthe motor 2504 results in a faster translation of the I-beam 2514, andthus, a faster firing speed. When the user desires a firing speed thatis in between the firing speed offered from the slow mode and the fastmode, the user can select the medium mode. In the medium mode, thecontrol circuit 2510 increases the velocity of the motor 2504 to a pointthat is greater than the velocity of the motor 2504 in the slow mode butless than the velocity of the motor 2504 in the fast mode. The output ofthe motor 2504 in the medium mode results in a medium translation of theI-beam 2514, and thus, a medium firing speed.

FIG. 86 is representative of one embodiment of the display 11100 duringa user selection process. For example, as the user applies a force F onthe articulation toggle 10510, the user is able to cycle through thevarious menu options 11112, 11114, 11116, 11118 relating to the velocitymode. The upwards arrowhead 11150 located above the articulation toggle10510 in FIG. 87 indicates that should a user press down on the upperhalf of the articulation toggle 10510, the user will scroll to the menuoption 11112, 11114, 11116, 11118 above the currently highlightedoption. The menu options may be configured to be continuous, whereinscrolling beyond the top option 11112 will result in the nexthighlighted option being the bottom option 11118 when the articulationtoggle 10510 is pressed once again. Alternatively, the user may not beable to scroll beyond the top or bottom menu options once they arereached. If the display 11100 possesses the touch screen capabilitiesmentioned above, the user may simply touch the menu options 11112,11114, 11116, 11118 to highlight the desired velocity mode instead of,or in combination with, the articulation toggle 10510.

As the user scrolls through the menu options 11112, 11114, 11116, 11118,the menu options change sizes. For example, in FIG. 86, the user hashighlighted the slow mode, as the second menu option 11124 has becomeenlarged. The reader will also recognize that the other three menuoptions 11122, 11126, 11128 have shrunk in an attempt to add furtheremphasis to the selected mode. The selected mode may additionally behighlighted and/or illuminated with a color, such as green, uponselection by the scroll menu.

FIG. 88 displays a chart 11200 indicating the various manners in whichthe menu options 11112, 11114, 11116, 11118 may be highlighted duringthe selection process discussed above. A menu option may be highlightedwhen the background of the menu option circle alternates between whiteand black shading 11210. For example, the menu option is highlightedwhen the menu option blinks and or flashes 11212. The flash 11212 can berecognized by the user, as a first background 11214 of the menu optionhas no color or is white, and a second background 11216 of the menuoption is black. The flash 11212 alternates between the first background11214 and the second background 11216. Additionally, the menu option maybe highlighted when the background of the menu option circle alternatesbetween white and colored shading 11230. For example, the menu option ishighlighted when the menu option blinks and or flashes 11212. The flash11212 can be recognized by the user, as a first background 11214 of themenu option has no color or is white, and a second background 11232 ofthe menu option is colored, such as green. The flash 11212 alternatesbetween the first background 11214 and the second background 11232. Athird exemplary manner in which a menu option may be highlighted is bysize differentiation 11220. For example, while the menu options may allhave the same color background 11222, an unselected menu option 11224may be reduced in size, whereas a highlighted menu option 11226 may beenlarged. These methods of highlighting are not meant to be limiting andcan be used in combination or separately.

In order to set and/or activate the highlighted menu option, the usermay slightly touch the firing trigger. Alternatively, the user may waita short period of time without any additional user input, and thecontrol circuit 2510 will automatically activate the highlighted menuoption. Once the menu option has been selected, the control circuit 2510may cause the screen to change to a velocity feedback system to enablethe user to monitor the velocity of the firing stroke during use.

FIGS. 89-91 illustrate a display 11300 depicting various velocityfeedback screens according to one aspect of this disclosure. The display11300 depicts a graphic image of an end effector staple cartridge 11312.The display 11300 comprises velocity indicia 11302 to indicate theselected menu option as well as the actual velocity of the displacementmember (e.g., I-beam 2514) during the firing cycle. In one aspect, thevelocity indicia 11302 comprises a shape or series of shapes that arefilled or shaded proportionally to the velocity, such as is depicted inFIGS. 89-91. The shape or shapes of the velocity indicia 11302 caninclude, e.g., an arcuate or any other suitable geometric shape. In oneaspect, the velocity indicia 11302 can comprise an arcuate graphic 11308comprising multiple graduations 11310 to indicate the actual velocityfrom 0-30 mm/sec, for example, of the displacement member. Alphanumericcharacters 11314 (0, 7, 12, and 30) are disposed about the perimeter ofthe arcuate graphic 11308 to indicate the actual velocity by a filled orshaded region 11316. The display 11300 shown in FIG. 89 is a slightlymodified version of the displays 11300′, 11300″ shown in FIGS. 90 and91. The arcuate graphic 11308 of the display 11300 may include cutoutsaround the alphanumeric character 11314 “12”, for example.

In addition, the velocity indicia 11302 further comprises a filled orshaded circle icon 11306 with one or more white arrows to indicate thecommand velocity, such that, for example, one arrow refers to lowvelocity or slow, two arrows refer to medium velocity, and three arrowsrefer to high velocity or fast. On the displays shown in FIGS. 89-91,the user has manually selected the fast mode from the alternate userselection screen as described above. An additional alphanumericcharacter 11304 indicates the units of velocity, e.g., mm/sec. As thevelocity of the displacement member increases or decreases, the shadedregion 11316 increases and decreases correspondingly. A status bar 11318at the bottom of the display 11300 indicates operation status as normal(e.g., green) or cautionary (e.g., yellow). In the examples shown inFIGS. 89 and 90 the status bar 11318 indicates normal operation. In theexample shown in FIG. 91, the status bar 11318 indicates cautionaryoperation. In one aspect, the fill or shade color of the velocityregions 11316, 11316′, 11316″ may be same as the fill or shade color ofthe status bars 11318, 11318′ to indicate normal or caution modes ofoperation.

As illustrated in FIG. 89, the actual velocity of the displacementmember is fast, approximately 20 mm/sec, as indicated by the shadedregion 11316. The command velocity, or the selected menu option, is setto high as indicated by the three arrowheads in the circle icon 11306.For at least the reason that the command velocity and the actualvelocity correspond to one another, the status bar 11318 is shadedgreen, indicating normal operation. As illustrated in FIG. 90, theactual velocity also is fast, approximately 14 mm/sec, as indicated bythe shaded region 11316′ and the command velocity is set to high asindicated by the three arrows in the circle icon 11306. For at least thereason that the command velocity and the actual velocity correspond toone another, the status bar 11318 is also shaded green, indicatingnormal operation. Turning to FIG. 91, the command velocity is set to thefast mode as indicated by the three arrows in the circle icon 11306, butthe actual velocity is approximately 10 mm/sec as indicated by theshaded region 11316″. Due to at least this discrepancy between thecommand velocity and the actual velocity, the status bar 11318′ isshaded yellow, indicating cautionary operation. The status bar 11318′indicating cautionary operation may alert a user, for example, to changethe velocity of the firing stroke, as the selected velocity isinappropriate due to, for example, tissue thickness. Additionally, theindication of cautionary operation may alert a user to a defectivesurgical instrument.

Various aspects of the subject matter described herein are set out inthe following numbered examples:

Example 1

A surgical instrument, comprising: a displacement member configured totranslate within the surgical instrument; a motor coupled to thedisplacement member, wherein the motor is configured to translate thedisplacement member at a velocity, and wherein the velocity is set by avelocity mode; a display; and a control circuit coupled to the motor andthe display, wherein the control circuit is configured to: cause thedisplacement member to translate a first distance; determine a firsttime period required for the displacement member to translate the firstdistance; cause the display to present a selection menu indicia that isindicative of the velocity mode, wherein the selection menu indiciadisplayed is limited by the first distance and the first time period;receive a user input corresponding to the velocity mode; and set themotor velocity based on the user input.

Example 2

The surgical instrument of Example 1, wherein the control circuit isfurther configured to cause the display to present a velocity indiciathat is indicative of the velocity of the displacement member.

Example 3

The surgical instrument of Example 1 through Example 2, wherein thevelocity mode comprises an automatic mode, a slow mode, a medium mode,and a fast mode.

Example 4

The surgical instrument of Example 3, wherein the velocity mode is setto the automatic mode in the absence of the user input.

Example 5

The surgical instrument of Example 1 through Example 4, wherein thesurgical instrument further comprises a position sensor coupled to thecontrol circuit.

Example 6

The surgical instrument of Example 5, wherein the position sensor isconfigured to monitor a position of the displacement member.

Example 7

The surgical instrument of Example 5 through Example 6, wherein thecontrol circuit is further configured to determine a velocity of thedisplacement member via the position sensor.

Example 8

A surgical instrument, comprising: a displacement member configured totranslate within the surgical instrument; a motor coupled to thedisplacement member, wherein the motor is configured to translate thedisplacement member at a velocity, wherein the velocity is defined by avelocity mode; a display; and a control circuit coupled to the motor andthe display, wherein the control circuit is configured to: cause thedisplacement member to translate a first distance; determine a firsttime period required for the displacement member to translate the firstdistance; receive a first user input; cause the display to present aselection menu indicia that is indicative of the velocity mode inresponse to the first user input, wherein the selection menu indiciadisplayed is limited by the first distance and the first time period;receive a second user input corresponding to the velocity mode; and setthe motor velocity based on the second user input.

Example 9

The surgical instrument of Example 8, wherein the control circuit isfurther configured to cause the display to present a velocity indiciathat is indicative of the velocity of the displacement member.

Example 10

The surgical instrument of Example 9, wherein the display presents theselection menu indicia during a first time period and the velocityindicia during a second time period.

Example 11

The surgical instrument of Example 10, wherein the first time period isdifferent than the second time period.

Example 12

The surgical instrument of Example 10 through Example 11, wherein thefirst time period is the same as the second time period.

Example 13

The surgical instrument of Example 8 through Example 12, wherein thevelocity mode comprises an automatic mode, a slow mode, a medium mode,and a fast mode.

Example 14

The surgical instrument of Example 13, wherein the velocity mode is setto the automatic mode by default.

Example 15

A method of operating a surgical instrument, the surgical instrumentcomprising a displacement member configured to translate within thesurgical instrument, a motor coupled to the displacement member totranslate the displacement member at a velocity, a display, and acontrol circuit coupled to the motor and the display, the methodcomprising: causing, by the control circuit, the displacement member totravel a first distance; measuring, by the control circuit, a first timeperiod required for the displacement member to translate the firstdistance; presenting, by the control circuit, an indicia on the displaythat is indicative of a velocity mode for the displacement member,wherein the indicia displayed is limited by the first distance and thefirst time period; receiving, by the control circuit, a user inputcorresponding to the velocity mode; and setting, by the control circuit,the motor velocity based on the user input.

Example 16

The method of Example 15, further comprising presenting, by the controlcircuit, a velocity indicia on the display that is indicative of thevelocity of the displacement member.

Example 17

The method of Example 15 through Example 16, further comprisingpresenting, by the control circuit, on the display the velocity mode,wherein the velocity mode comprises an automatic mode, a slow mode, amedium mode, and a fast mode.

Example 18

The method of Example 16 through Example 17, further comprisingcontrolling, by the control circuit, the motor to in the automatic modein the absence of a user input.

Example 19

The method of Example 16 through Example 18, further comprisingpresenting, by the control circuit, on the display the velocity mode setto the automatic mode in the absence of a user input.

Example 20

The method of Example 15 through Example 19, further comprisingmonitoring, by the control circuit, the velocity of the displacementmember.

Closed Loop Feedback Control of Motor Velocity of a Surgical Staplingand Cutting Instrument Based on System Conditions

During use of a motorized surgical stapling and cutting instrument it ispossible that the battery may overheat due to externally applied loadsand cause the motor to stall. Therefore, it may be desirable tointerrogate the voltage on the battery during a portion of the firingstroke when the system is loaded to assess battery capability andadjusting the firing velocity of the cutting member or the firing memberbased on this feedback.

The disclosure now turns to a closed loop feedback system forcontrolling motor velocity based on a variety of conditions. In oneaspect, a logic flow diagram of a process of a control program or logicconfiguration is provided for controlling motor velocity based onbattery condition. In another aspect, a logic flow diagram of a processof a control program or logic configuration is provided for controllingmotor velocity based on stalled condition during a normal firing cycle.In another aspect, a logic flow diagram of a process of a controlprogram or logic configuration is provided for controlling motorvelocity while in manual mode. In another aspect, a logic flow diagramof a process of a control program or logic configuration is provided forcontrolling motor velocity based on stalled condition during a normalfiring cycle and implementing a forced pause in the firing cycle. Inanother aspect, a logic flow diagram of a process of a control programor logic configuration is provided for controlling motor velocity basedon stalled condition during a normal firing and reducing the velocityone level once the firing cycle is restarted. In another aspect, a logicflow diagram of a process of a control program or logic configuration isprovided for controlling motor velocity based on stalled conditionduring a normal firing cycle in manual mode and reducing velocity onelevel once the firing cycle is restarted. In another aspect, a logicflow diagram of a process depicting a control program or logicconfiguration is provided for controlling motor velocity based onstalled condition during a normal firing cycle and pausing the firingcycle until the user releases the firing trigger. In another aspect, alogic flow diagram of a process of a control program or logicconfiguration is provided for controlling motor velocity duringtransition between velocities. These aspects are described in moredetail herein below with reference to FIGS. 92-99.

A motor stall condition is when the rotational output of the motor dropsto zero. Stall torque is the torque which is produced by the motor whenthe output rotational speed is zero. It may also mean the torque loadthat causes the output rotational speed of the motor to become zero,i.e., to cause stalling. Stalling is a condition when the motor stopsrotating. This condition occurs when the load torque is greater than themotor shaft torque, i.e., break down torque condition. In this conditionthe motor draws maximum current but the motor shaft does not rotate. Thecurrent is called the stalling current. Electric motors continue toprovide torque when stalled. However, electric motors left in a stalledcondition are prone to overheating and possible damage since the currentflowing is maximum under these conditions. The maximum torque anelectric motor can produce in the long term when stalled without causingdamage is called the maximum continuous stall torque.

With reference to FIG. 14, a motor stall condition can be detected usinga variety of techniques. In one aspect, a motor stall can be detected bymonitoring the energy source 2512 to the motor 2504. If the voltagedrops below a predetermined threshold, it may be an indication of amotor stall condition. In another aspect, a motor stall condition can bedetected by monitoring the current through the motor 2504 via thecurrent sensor 2536. If the current sensed by the current sensor 2536increases above a predetermined threshold to a value greater than thestalling current, the motor 2504 may be stalled or stalling. In anotheraspect, the current sensor 2536 may be placed in series with the groundleg of the motor 2504. In another aspect, a motor stall condition may bedetected by monitoring the current applied to the motor 2504 relative tothe actual displacement of a displacement member, such as the I-beam2514, monitored by the position sensor 2534. If the motor current isgreater than expected, near or greater than the stalling current, andthe actual velocity is lower than the command velocity, the motor maystalled or stalling. The motor 2504 may suffer damage by overheating ifa motor stall condition is not corrected in a timely manner.

Accordingly, turning now to FIG. 92, there is illustrated a logic flowdiagram of a process 11500 depicting a control program or logicconfiguration for controlling motor velocity based on battery conditionaccording to one aspect of this disclosure. With reference also to FIGS.1-15 and in particular FIG. 14, in one aspect, the control circuit 2510is configured to interrogate the energy source 2512 to determine thevoltage on the battery during a portion of the firing cycle when thesurgical instrument 2500 is loaded to assess battery capability andadjust the firing velocity of the displacement member (e.g., drivemember 120, firing member 220, firing bar 172, I-beam 2514, etc.) basedon this feedback. As previously discussed, the firing velocity of thedisplacement member is controlled by the control circuit 2510 based onvarious feedback conditions. The control circuit 2510 determines a newvelocity of the displacement member and applies a motor set point 2522to the motor control 2508, which in turn applies the motor drive signal2524 to the motor 2504. The set or command velocity of the motor 2504 isapplied to a transmission 2506. The actual velocity of the displacementmember is determined based on feedback from the position sensor 2534,energy source 2512, current sensor 2536, timer/counter 2531, or sensors2538, alone or in combination. As previously discussed, factors that mayaffect the actual velocity of the displacement member include externalinfluences such as tissue thickness, tissue, type, or system conditions.The determination of battery condition, such as a battery overheatingcondition, informs the control circuit 2510 of the firing velocity. Asan example, the control circuit 2510 measures the voltage, internalresistance, and/or current in/through the battery during the first0.080″ to 0.12″ (2 mm to 3 mm) and in one example 0.09″ (2.286 mm) oftravel of the displacement member, (e.g., when the system is loaded). Ifthe voltage V_(b) of a 12V battery is <9V, the internal resistance R_(b)of the battery is above a threshold, or the current I_(b) is below athreshold, then it is likely that the battery is in an overheated state.The control circuit 2510 immediately sets the firing velocity to thelowest setting for the entire firing cycle.

With reference now to FIGS. 14 and 92, according to the process 11500,the control circuit 2510 initiates 11502 a firing cycle of thedisplacement member and continually samples 11504 the energy source 2512during the initial firing stage (e.g., during the first 0.090″ of travelas determined by the position sensor 2534). The sampled voltage iscompared 11506 to a threshold voltage. In one example, for a 12V energysource 2512 the threshold is set to 9V. The threshold may be adjusted toaccommodate system voltage requirements. If the sampled voltage isgreater than or equal to the threshold voltage, the control circuit 2510continues along the NO branch and continues 11508 the firing cycle untilthe sampled voltage is less than the threshold voltage, the controlcircuit 2510 continues along the YES branch and the control circuit 2510communicates 11510 the weak battery condition via a status indicatorsuch as a display 43, 743 (FIGS. 2, 5B, 6). The status indicator may bean LED, a display, a buzzer, among others. Upon communicating 11510 theweak battery status, the control circuit 2510 determines 11512 if thesurgical instrument 2500 device is in automatic mode. If the surgicalinstrument 2500 is in automatic mode the control circuit 2510 continuesalong the YES branch and the control circuit 2510 converts 11514 thesurgical instrument 2500 to manual mode and reduces 11516 the commandvelocity of the motor 2504 slow. If the surgical instrument 2500 is notin automatic mode the control circuit 2510 continues along the NO branchand the control circuit 2510 reduces 11516 the command velocity of themotor 2504 slow. In some aspects, a slow command velocity may be lessthan 10 mm/sec and in some aspects may be less than 5 mm/sec.

FIG. 93 is a logic flow diagram of a process 11520 depicting a controlprogram or logic configuration for controlling motor velocity based onstalled condition during a normal firing cycle according to one aspectof this disclosure. Generally, if the motor stalls during a normalfiring cycle, the process 11520 forces the motor to operate in theslowest mode for the rest of the firing cycle. Thus, if the motorstalls, the remaining stroke is executed at a slow velocity.

With reference now to FIGS. 14 and 93, according to the process 11520,the control circuit 2510 initiates 11522 a firing cycle of thedisplacement member at a medium command velocity such as 12 mm/sec.During the firing cycle, the control circuit 2510 checks 11524 for amotor stall condition and if it determines 11526 that the motor is notstalled, the control circuit 2510 continues along the NO branch andcontinues 11532 the firing cycle until the motor 2504 stalls. At whichtime the control circuit 2510 continues along the YES branch and reduces11528 the command velocity to slow and indicates 11530 the status by wayof warning light or other indicator such as display 43, 743 (FIGS. 2,5B, 6). Upon reducing 11528 the command velocity to slow, the controlcircuit 2510 continues 11532 the firing cycle and checking 11524 forstalls until the motor 2504 stalls or the displacement member reachesthe end of stroke. As previously discussed, a slow command motorvelocity may be less than 10 mm/sec and in some aspects may be less than5 mm/sec. In this example, the command velocity is set to 9 mm/sec.

FIG. 94 is a logic flow diagram of a process 11540 depicting a controlprogram or logic configuration for controlling motor velocity while inmanual mode according to one aspect of this disclosure. Generally, whilethe surgical instrument 2500 is in manual mode, the motor is at risk ofstalling and the control circuit displays a warning. If the commandvelocity of the motor is not paused or reduced by the user, the devicewill automatically enter into low speed for the remainder of the firingcycle. Accordingly, while the surgical instrument is in manual mode andthe risk of stalling is detected by the control circuit, the user isgiven the opportunity to manually adjust the command velocity to avoid amotor stall.

With reference now to FIGS. 14 and 94, according to the process 11540,the control circuit 2510 selects 11542 manual mode upon receiving arequest from the user and initiates 11544 a firing cycle of thedisplacement member. During the firing cycle, the control circuit 2510checks 11546 for a motor stall and if the control circuit 2510 does notdetect 11548 low velocity, the control circuit 2510 proceeds along theNO branch and the control circuit 2510 continues 11550 the firing cycleuntil a low velocity is detected 11548. When a low velocity is detected11548, the control circuit 2510 continues along the YES branch and thecontrol circuit indicates 11552 the low velocity status by way ofdisplay 43, 743 (FIGS. 2, 5B, 6), warning light, and display a countdowntimer to provide the user some time to manually reduce the motorvelocity. This period of time may be a few seconds and up to 10 seconds,for example. After the countdown timer times out, the control circuit2510 determines 11554 whether the user has selected to manually adjustthe velocity of the motor 2504 or pause the motor 2504. If the userselected to manually adjust the velocity of the motor 2504 or pause themotor 2504 the control circuit 2510 continues along the YES branch andthe control circuit 2510 detects 11548 for low velocity and the process11540 continues until the user elects not the manually adjust thevelocity of the motor 2504 or pause the motor 2504. At which point, thecontrol circuit 2510 continues along the NO branch and reduces 11556 thevelocity of the motor 2504 to slow speed and continues the firing cycle.The process continues until the displacement member reaches the end ofstroke. As previously discussed, a slow command motor velocity may beless than 10 mm/sec and in some aspects may be less than 5 mm/sec. Inthis example, the command velocity is reduced 11556 to 9 mm/sec.

FIG. 95 is a logic flow diagram of a process 11560 depicting a controlprogram or logic configuration for controlling motor velocity based onstalled condition during a normal firing cycle and implementing a forcedpause in the firing cycle according to one aspect of this disclosure.Generally, when the motor stalls during a normal firing cycle, thecontrol circuit stops the motor and forces a pause in the firing cycle.The duration of the pause depends on the command velocity of the motorat the time of the stall. Faster motor velocities may require longerpauses, etc. Accordingly, if the motor stalls, the control circuit stopsthe motor and forces a pause before allowing the motor to restart at thesame velocity at the time of the stall.

With reference now to FIGS. 14 and 95, according to the process 11560,the control circuit 2510 initiates 11562 a firing cycle of thedisplacement member and stores 11564 the current velocity of the motor(e.g., SLOW: 0<V<10 mm/sec; MEDIUM: 10 mm/sec V 12.5 mm/sec; FAST: 12.5mm/sec <V<15 mm/sec) and checks 11566 for a motor stall condition. Thecontrol circuit 2510 then determines 11568 whether the motor 2504stalled. If the motor 2504 stalled, the control circuit continues alongthe NO branch and the control circuit 2510 continues 11570 the firingcycle and checks 11566 for a motor stall condition until the motor 2504stalls. The control circuit 2510 then proceeds along the YES branch andevaluates three conditions. A first evaluation determines 11572 if theprevious velocity of the motor 2504 was FAST and if true, the controlcircuit 2510 sets 11574 a delay greater than or equal to 2 seconds andless than or equal to 5 seconds and continues 11576 the firing cycle atthe stored velocity. At the same time, the control circuit 2510indicates 11578 the status of the surgical instrument 2500 by displayingor showing a warning light, among other feedback techniques such asdisplay 43, 743 (FIGS. 2, 5B, 6). A second evaluation determines 11580if the previous velocity of the motor 2504 was MEDIUM and if true, thecontrol circuit 2510 sets 11582 a delay greater than or equal to 1second and less than 2 seconds and continues 11584 the firing cycle atthe stored velocity. At the same time, the control circuit 2510indicates 11586 the status by displaying or showing a warning light,among other feedback techniques such as display 43, 743. A thirdevaluation determines 11588 if the previous velocity of the motor 2504was SLOW and if true, the control circuit 2510 sets 11590 a 0 to 1second delay and preferably a 0 to 0.25 seconds delay and continues11592 the firing cycle at the stored velocity. At the same time, thecontrol circuit 2510 indicates 11594 the status by displaying or showinga warning light, among other feedback techniques such as display 43,743. The process 11560 continues until the displacement member reachesthe end of stroke.

FIG. 96 is a logic flow diagram of a process 11600 depicting a controlprogram or logic configuration for controlling motor velocity based onstalled condition during a normal firing cycle and reducing the velocityone level once the firing cycle is restarted according to one aspect ofthis disclosure. Generally, when the motor stalls during a normal firingcycle, the velocity of the motor is reduced one level below the currentmotor velocity once the firing cycle is restarted. If the motor velocityis already at the slowest speed, a forced pause of a predeterminedduration is required before restarting the firing cycle at the slowestspeed again. Accordingly, if the motor stalls, the control circuit slowsdown the motor velocity to one level below stored velocity.

With reference now to FIGS. 14 and 96, according to the process 11600,the control circuit 2510 initiates 11602 a firing cycle of thedisplacement member and stores 11604 the current velocity of the motor(e.g., SLOW: V<10 mm/sec; MEDIUM: 10 mm/sec V 12.5 mm/sec; FAST: V>12.5mm/sec) and checks 11606 for a motor stall condition. The controlcircuit 2510 then determines 11608 whether the motor 2504 stalled. Ifthe motor 2504 stalled, the control circuit 2510 continues along the NObranch and the control circuit 2510 continues 11610 the firing cycle andchecks 11606 for a motor stall condition until the motor 2504 stalls.The control circuit 2510 then proceeds along the YES branch andevaluates three conditions. A first evaluation determines 11612 if theprevious velocity of the motor 2504 was FAST and if true, the controlcircuit 2510 auto-adjusts 11614 the velocity of the motor 2504 to MEDIUMand reinitiates 11602 the firing cycle at the new MEDIUM velocity. Atthe same time, the control circuit 2510 indicates 11616 the status ofthe surgical instrument 2500 by displaying or showing a warning light,among other feedback techniques such as display 43, 743 (FIGS. 2, 5B,6). A second evaluation determines 11618 if the previous velocity of themotor 2504 was MEDIUM and if true, the control circuit 2510 auto-adjusts11620 the velocity of the motor 2504 to SLOW and reinitiates 11602 thefiring cycle at the new SLOW velocity. At the same time, the controlcircuit 2510 indicates 11622 the status by displaying or showing awarning light, among other feedback techniques such as display 43, 743.A third evaluation determines 11624 if the previous velocity of themotor 2504 was SLOW and if true, the control circuit 2510 forces a pause11626 of a predetermined duration. After the predetermined pause, thecontrol circuit 2510 reinitiates 11602 the firing cycle at the SLOWvelocity. At the same time, the control circuit 2510 indicates 11628 thestatus by displaying or showing a warning light, among other feedbacktechniques such as display 43, 743. The process 11600 continues untilthe displacement member reaches the end of stroke.

FIG. 97 is a logic flow diagram of a process 11630 depicting a controlprogram or logic configuration for controlling motor velocity based onstalled condition during a normal firing cycle in manual mode andreducing velocity one level once the firing cycle is restarted accordingto one aspect of this disclosure. Generally, when the motor stallsduring a normal firing cycle while in manual mode, the control circuitreduces the velocity of the motor one level once the firing cycle isrestarted. If already at the slowest speed, the control circuit forcespause of a predetermined duration before restarting the firing cycle atthe slowest speed again. The user can only choose a speed that is slowerthan the speed at which the stall occurred for the remainder of thefiring cycle. Accordingly, if the motor stalls while in manual mode, thecontrol circuit lowers the velocity of the motor one level and locks outthe previous higher motor velocities.

With reference now to FIGS. 14 and 97, according to the process 11630,the control circuit 2510 initiates 11632 a firing cycle of thedisplacement member and stores 11634 the current velocity of the motor(e.g., SLOW: V<10 mm/sec; MEDIUM: 10 mm/sec V 12.5 mm/sec; FAST: V>12.5mm/sec) and checks 11636 for a motor stall condition. The controlcircuit 2510 then determines 11638 whether the motor 2504 stalled. Ifthe motor 2504 stalled, the control circuit 2510 continues along the NObranch and the control circuit 2510 continues 11640 the firing cycle andchecks 11636 for a motor stall condition until the motor 2504 stalls.The control circuit 2510 then proceeds along the YES branch andevaluates three conditions. A first evaluation determines 11642 if theprevious velocity of the motor 2504 was FAST and if true, the controlcircuit 2510 reduces 11644 the velocity to MEDIUM and disables,inhibits, or blocks the FAST velocity. The control circuit 2510reinitiates 11632 the firing cycle at the new MEDIUM velocity whileblocking FAST. The control circuit 2510 may indicate the status of thesurgical instrument 2500 by displaying or showing a warning light, amongother feedback techniques. A second evaluation determines 11646 if theprevious velocity of the motor 2504 was MEDIUM and if true, the controlcircuit 2510 reduces 11648 the velocity of the motor 2504 to SLOW anddisables, inhibits, or blocks MEDIUM and FAST velocities. The controlcircuit 2510 reinitiates 11632 the firing cycle at the new SLOW velocitywhile blocking MEDIUM and FAST velocities. The control circuit 2510 mayindicate the status by displaying or showing a warning light, amongother feedback techniques. A third evaluation determines 11650 if theprevious velocity of the motor 2504 was SLOW and if true, the controlcircuit 2510 forces a pause 11652 of a predetermined duration. After thepredetermined pause, the control circuit 2510 reinitiates 11632 thefiring cycle at a velocity that is slower than the SLOW velocity atwhich the motor stall occurred for the remainder of the firing cycle. Atthe same time, the control circuit 2510 indicates 11628 the status bydisplaying or showing a warning light, among other feedback techniques.The process 11600 continues until the displacement member reaches theend of stroke.

FIG. 98 is a logic flow diagram 11660 of a process depicting a controlprogram or logic configuration for controlling motor velocity based onstalled condition during a normal firing cycle and pausing the firingcycle until the user releases the firing trigger according to one aspectof this disclosure. Generally, when the motor stalls during a normalfiring cycle, the control circuit pauses until the user (e.g., thesurgeon) releases the trigger. When the firing cycle is reinitiated, thecontrol circuit restarts at the same command velocity at which the motorstall occurred.

With reference now to FIGS. 14 and 98, according to the process 11660,the control circuit 2510 initiates 11622 a firing cycle of thedisplacement member and checks 11664 for a motor stall. If the motor isnot stalled 11666, the control circuit 2510 continues along the NObranch and checks 11664 for a motor stall until the motor 2504 stalls.If there is a motor stall, the control circuit 2510 proceeds along theYES branch and pauses 11668 the motor 2504 and halts the firing cycle.The control circuit 2510 indicates 11674 the status and warns of a motorstall condition on a display 43, 743 (FIGS. 2, 5B, 6) and instructs theuser (e.g., the surgeon) to release the trigger. The control circuit2510 then determines 11672 if the trigger is released and continuesalong the NO branch until the trigger is released. The control circuit2510 then proceeds along the YES branch and continues 11670 the firingcycle until the motor 2504 stalls or the displacement member reaches theend of stroke.

FIG. 99 is a logic flow diagram of a process 11680 depicting a controlprogram or logic configuration for controlling motor velocity duringtransition between velocities according to one aspect of thisdisclosure. Generally, during time, distance, or velocity based controlschemes, the transition from one velocity to another likely affects thetarget value for the next comparison. To avoid constant velocity changestriggered primarily due to changes in command velocity, the zone (orzones) immediately following the latest velocity change are excludedfrom consideration. In one aspect, the return velocity is always at thefastest velocity.

With reference now to FIGS. 14 and 99, according to the process 11680,the control circuit 2510 initiates 11682 a firing cycle of thedisplacement member and monitors 11684 the position of the displacementmember based on the position sensor 2534 until the displacement memberreaches a target for comparison of changes in velocity. When thedisplacement member reaches a target comparison position, the controlcircuit 2510 determines 11686 whether the previous zone initiated achange in velocity. If the previous zone initiated a change in velocity,the control circuit 2510 continues along the YES branch and continuesfiring 11688 at the current command velocity and monitors 11684 if thedisplacement member has reached a target for comparison. The processcontinues until the control circuit 2510 determines 11686 that theprevious zone did not initiate a change in velocity. The control circuit2510 proceeds along the NO branch and compares 11690 the expectedvelocity value of the displacement member with the actual velocity valueof the displacement member. The control circuit 2510 sets 11692 the newcommand velocity of the motor 2504 for the next zone based on theresults of the comparison 11690. After setting 11692 the new commandvelocity of the motor 2504, the control circuit determines 11694 if thedisplacement member is located in the final zone. If the displacementmember is not located in the final zone, the control circuit 2510continues along the NO branch and continues firing at the new commandvelocity and the process continues until the displacement member islocated in the final zone. At this point, the control circuit 2514continues firing 11696 until the displacement member reaches the end ofstroke. Otherwise, the control circuit 2510 continues 11688 firing thedisplacement member at the current command velocity.

Various aspects of the subject matter described herein are set out inthe following numbered examples:

Example 1

A surgical instrument, comprising: a displacement member configured totranslate within the surgical instrument over a plurality of predefinedzones; an energy source; a motor coupled to the displacement member totranslate the displacement member; a control circuit coupled to theenergy source and the motor; a position sensor coupled to the controlcircuit, the position sensor configured to monitor the position of thedisplacement member; wherein the control circuit is configured to:initiate firing the displacement member at a predetermined electricalload on the energy source, wherein the predetermined electrical load isapplied to the motor to actuate the displacement member; monitor theposition of the displacement member via the position sensor; continuallysample a voltage of the energy source during a first interval of travelof the displacement member; compare the sampled voltage to a thresholdvoltage; and continue firing the displacement at the first velocity whenthe sampled voltage is greater than or equal to the threshold voltage;or adjust the first velocity when the sampled voltage is less than thethreshold voltage.

Example 2

The surgical instrument of Example 1, wherein when the sampled voltageis less than the threshold voltage the control circuit is furtherconfigured to determine if the surgical instrument is in automatic modeor manual mode.

Example 3

The surgical instrument of Example 2, wherein when the surgicalinstrument is in automatic mode the control circuit is furtherconfigured to convert the operation of the surgical instrument to manualmode.

Example 4

The surgical instrument of Example 3, wherein the control circuit isfurther configured to reduce the command velocity to a second velocity,wherein the second velocity is slower than the first velocity.

Example 5

The surgical instrument of Example 4, wherein the second velocity isgreater than zero and less than 10 mm/sec.

Example 6

The surgical instrument of Example 1 through Example 5, wherein thefirst interval is between 2 mm and 3 mm.

Example 7

The surgical instrument of Example 1 through Example 6, wherein thecontrol circuit is configured to communicate status of energy sourcewhen the sampled voltage is less than the threshold voltage.

Example 8

A surgical instrument, comprising: a displacement member configured totranslate within the surgical instrument; a motor comprising a shaft,the motor coupled to the displacement member to translate thedisplacement member; a control circuit coupled to the motor; wherein thecontrol circuit is configured to: initiate firing the displacementmember at a command velocity set to a first velocity, wherein thecommand velocity is the velocity applied to the motor; check for a motorstall condition; and continue firing the displacement at the firstvelocity when the motor is not stalled; or reduce the command velocityto a second velocity, wherein the second velocity is slower than thefirst velocity.

Example 9

The surgical instrument of Example 8, wherein the first velocity isbetween 10 mm/sec and 12 mm/se and the second velocity is less than 9mm/sec.

Example 10

The surgical instrument of Example 8 through Example 9, wherein thecontrol circuit is configured to indicate a motor stall warning.

Example 11

The surgical instrument of Example 10, wherein the control circuit isconfigured to: set the surgical instrument in manual mode based on areceived input; detect a low motor velocity condition; indicate the lowmotor velocity condition for a predetermined period of time; and monitorfor a manual command velocity adjustment or pause; and reduce thecommand velocity when the manual command velocity adjustment or pause isnot detected.

Example 12

The surgical instrument of Example 8 through Example 11, wherein thecontrol circuit is configured to: store a current command velocity inmemory as a fast velocity, a medium velocity, or a slow velocity,wherein the fast velocity is greater than the medium velocity and themedium velocity is greater than the slow velocity; and when a motorstall condition is detected, the control circuit is configured to: pausethe motor for a first delay when the stored command velocity is a fastvelocity and continue firing the displacement member at the fastvelocity; pause the motor for a second when the stored command velocityis a medium velocity and continue firing the displacement member at themedium velocity; or pause the motor for a third delay when the storedcommand velocity is a slow velocity and continue firing the displacementmember at the slow velocity; wherein the first delay is greater thansecond delay and the second delay is greater than the third delay.

Example 13

The surgical instrument of Example 12, wherein: the slow velocity isgreater than zero and less 10 mm/sec; the medium velocity is greaterthan or equal to 10 mm/sec and less than or equal to 12.5 mm/sec; andthe fast velocity is greater than 12.5 mm/sec and less than 15 mm/sec.

Example 14

The surgical instrument of Example 12 through Example 13, wherein: thefirst delay is greater than or equal to 2 seconds and less than fiveseconds; the second delay is greater than or equal to 1 second and lessthan two seconds; and the third delay greater than 0 and less than 1second.

Example 15

The surgical instrument of Example 8 through Example 14, wherein thecontrol circuit is configured to: store a current command velocity inmemory as a fast velocity, a medium velocity, or a slow velocity,wherein the fast velocity is greater than the medium velocity and themedium velocity is greater than the slow velocity; and when a motorstall condition is detected, the control circuit is configured to: autoadjust the command velocity to a medium velocity when the stored commandvelocity is a fast velocity; auto adjust the command velocity to a slowvelocity when the stored command velocity is a medium velocity; andpause the motor when the stored command velocity is a slow velocity.

Example 16

The surgical instrument of Example 8 through Example 15, wherein thecontrol circuit is configured to: pause the firing store a currentcommand velocity in memory as a fast velocity, a medium velocity, or aslow velocity, wherein the fast velocity is greater than the mediumvelocity and the medium velocity is greater than the slow velocity; andwhen a motor stall condition is detected, the control circuit isconfigured to: reduce the command velocity to a medium velocity andinhibit a fast velocity when the stored command velocity is a fastvelocity; reduce the command velocity to a slow velocity and inhibit amedium velocity and a fast velocity when the stored command velocity isa medium velocity; and pause the motor when the stored command velocityis a slow velocity.

Example 17

The surgical instrument of Example 8 through Example 16, wherein when amotor stall condition is detected, the control circuit is configured to:pause the motor; indicate a warning of motor stall and instruct user torelease trigger; monitor release of the trigger; and continue firing thedisplacement member when the trigger is released.

Example 18

A surgical instrument, comprising: a displacement member configured totranslate within the surgical instrument over a plurality of predefinedzones; an energy source; a motor coupled to the displacement member totranslate the displacement member; a control circuit coupled to theenergy source and the motor; a position sensor coupled to the controlcircuit, the position sensor configured to monitor the position of thedisplacement member; wherein the control circuit is configured to:initiate firing the displacement member at a command velocity set to afirst velocity, wherein the command velocity is the velocity applied tothe motor; monitor the position of the displacement member in a currentzone until the displacement member reaches a target position forcomparison; when the displacement member reaches the target position,determine whether a change in command velocity was initiated in aprevious zone prior to the current zone; and continue firing thedisplacement member at the command velocity when a change in commandvelocity was initiated in the previous zone.

Example 19

The surgical instrument of Example 18, wherein when a change in commandvelocity was not initiated in the previous zone, the control circuit isconfigured to: compare an expected velocity of the displacement memberto an actual velocity of the displacement member; and adjust the commandvelocity based on the results of the comparison.

Example 20

The surgical instrument of Example 19, wherein the control circuit isconfigured to: determine when the displacement is in a final zone; andcontinue firing the displacement member until an end of stroke isreached.

Example 21

The surgical instrument of Example 19 through Example 20, wherein thecontrol circuit is configured to continue firing the displacement memberat the current command velocity when the displacement member is not inthe final zone.

Techniques for Closed Loop Control of Motor Velocity of a SurgicalStapling and Cutting Instrument

FIG. 100 is a logic flow diagram depicting a process 8000 of a controlprogram or a logic configuration for adjusting the velocity of adisplacement member based on the magnitude of one or more error termsbased on the difference between an actual velocity of the displacementmember and a command or directed velocity of the displacement memberover a specified increment of time or distance according to one aspectof this disclosure. The process 8000 may be executed by the surgicalinstrument 2500 (e.g., the control circuit 2510). Accordingly, withreference also to FIG. 14, the control circuit 2510 sets 8002 a directedvelocity of the displacement member, such as, for example, the I-beam2514. The directed velocity is the same as the command velocity, whichis set by the control circuit 2510. For example, to set the command ordirected velocity of the displacement member, the control circuit 2510applies a motor set point 2522 to a motor control 2508 which applies amotor drive signal 2524 to the motor 2504 to advance the displacementmember (e.g., I-beam 2514) through a transmission 2506. The controlcircuit 2510 determines 8004 the actual velocity of the displacementmember utilizing feedback signals from the position sensor 2534 and thetimer/counter circuit 2531. The control circuit 2510 determines 8006 thedifference between the directed velocity and the actual velocity of thedisplacement member and controls 8008 the velocity of the displacementmember based on a magnitude of the error.

In accordance with the process 8000, the error may be based on at leastone of a short term error (S), cumulative error (C), rate of changeerror (R), and number of overshoots error (N) as described above inconnection with FIGS. 16-22. In one aspect, the surgical instrument 2500further comprises an end effector 2502, where the displacement member(e.g., I-beam 2514) is configured to translate within the end effector2502. Further, in various aspects, the error may be determined over apredetermined increment of distance or time. In one aspect, the controlcircuit 2510 is configured to determine a zone in which the displacementmember is located.

Various aspects of the subject matter described herein are set out inthe following numbered examples:

Example 1

A method of adjusting velocity in a motorized surgical instrument, thesurgical instrument comprising a displacement member configured totranslate within the surgical instrument over a plurality of predefinedzones, a motor coupled to the displacement member to translate thedisplacement member, a control circuit coupled to the motor, a positionsensor coupled to the control circuit, the position sensor configured tomeasure the position of the displacement member, and a timer circuitcoupled to the control circuit, the timer circuit configured to measureelapsed time, the method comprising: setting, by the control circuit, adirected velocity of the displacement member; determining, by thecontrol circuit, an actual velocity of the displacement member;determining, by the control circuit, an error between the directedvelocity of the displacement member and the actual velocity of thedisplacement member; and controlling, by the control circuit, the actualvelocity of the displacement member based on the magnitude of the error.

Example 2

The method of Example 1, wherein the error is based on at least one of ashort term error (S), cumulative error (C), rate of change error (R),and number of overshoots error (N).

Example 3

The method of Example 1 through Example 2, wherein the surgicalinstrument further comprises an end effector, wherein the displacementmember is configured to translate within the end effector.

Example 4

The method of Example 1 through Example 3, wherein the error isdetermined over a predetermined increment of time.

Example 5

The method of Example 1 through Example 4, wherein the error isdetermined over a predetermined increment of distance.

Example 6

The method of Example 1 through Example 5, further comprisingdetermining, by the control circuit, a zone in which the displacementmember is located.

The functions or processes 8000, 8600, 8700, 8800, 9400, 9450, 9800,9850, 10400, 10450, 10550, 11000, 11500, 11520, 11540, 11560, 11600,11630, 11660, 11680 described herein may be executed by any of theprocessing circuits described herein, such as the control circuit 700described in connection with FIGS. 5-6, the circuits 800, 810, 820described in FIGS. 7-9, the microcontroller 1104 described in connectionwith FIGS. 10 and 12, and/or the control circuit 2510 described in FIG.14.

Aspects of the motorized surgical instrument may be practiced withoutthe specific details disclosed herein. Some aspects have been shown asblock diagrams rather than detail. Parts of this disclosure may bepresented in terms of instructions that operate on data stored in acomputer memory. An algorithm refers to a self-consistent sequence ofsteps leading to a desired result, where a “step” refers to amanipulation of physical quantities which may take the form ofelectrical or magnetic signals capable of being stored, transferred,combined, compared, and otherwise manipulated. These signals may bereferred to as bits, values, elements, symbols, characters, terms,numbers. These and similar terms may be associated with the appropriatephysical quantities and are merely convenient labels applied to thesequantities.

Generally, aspects described herein which can be implemented,individually and/or collectively, by a wide range of hardware, software,firmware, or any combination thereof can be viewed as being composed ofvarious types of “electrical circuitry.” Consequently, “electricalcircuitry” includes electrical circuitry having at least one discreteelectrical circuit, electrical circuitry having at least one integratedcircuit, electrical circuitry having at least one application specificintegrated circuit, electrical circuitry forming a general purposecomputing device configured by a computer program (e.g., a generalpurpose computer or processor configured by a computer program which atleast partially carries out processes and/or devices described herein,electrical circuitry forming a memory device (e.g., forms of randomaccess memory), and/or electrical circuitry forming a communicationsdevice (e.g., a modem, communications switch, or optical-electricalequipment). These aspects may be implemented in analog or digital form,or combinations thereof.

The foregoing description has set forth aspects of devices and/orprocesses via the use of block diagrams, flowcharts, and/or examples,which may contain one or more functions and/or operation. Each functionand/or operation within such block diagrams, flowcharts, or examples canbe implemented, individually and/or collectively, by a wide range ofhardware, software, firmware, or virtually any combination thereof. Inone aspect, several portions of the subject matter described herein maybe implemented via Application Specific Integrated Circuits (ASICs),Field Programmable Gate Arrays (FPGAs), digital signal processors(DSPs), Programmable Logic Devices (PLDs), circuits, registers and/orsoftware components, e.g., programs, subroutines, logic and/orcombinations of hardware and software components. logic gates, or otherintegrated formats. Some aspects disclosed herein, in whole or in part,can be equivalently implemented in integrated circuits, as one or morecomputer programs running on one or more computers (e.g., as one or moreprograms running on one or more computer systems), as one or moreprograms running on one or more processors (e.g., as one or moreprograms running on one or more microprocessors), as firmware, or asvirtually any combination thereof, and that designing the circuitryand/or writing the code for the software and or firmware would be wellwithin the skill of one of skill in the art in light of this disclosure.

The mechanisms of the disclosed subject matter are capable of beingdistributed as a program product in a variety of forms, and that anillustrative aspect of the subject matter described herein appliesregardless of the particular type of signal bearing medium used toactually carry out the distribution. Examples of a signal bearing mediuminclude the following: a recordable type medium such as a floppy disk, ahard disk drive, a Compact Disc (CD), a Digital Video Disk (DVD), adigital tape, a computer memory, etc.; and a transmission type mediumsuch as a digital and/or an analog communication medium (e.g., a fiberoptic cable, a waveguide, a wired communications link, a wirelesscommunication link (e.g., transmitter, receiver, transmission logic,reception logic, etc.).

The foregoing description of these aspects has been presented forpurposes of illustration and description. It is not intended to beexhaustive or limiting to the precise form disclosed. Modifications orvariations are possible in light of the above teachings. These aspectswere chosen and described in order to illustrate principles andpractical application to thereby enable one of ordinary skill in the artto utilize the aspects and with modifications as are suited to theparticular use contemplated. It is intended that the claims submittedherewith define the overall scope.

The invention claimed is:
 1. A method of adjusting velocity in amotorized surgical instrument, the motorized surgical instrumentcomprising a displacement member configured to translate within themotorized surgical instrument over a plurality of predefined zones, amotor coupled to the displacement member to translate the displacementmember, a control circuit coupled to the motor, a position sensorcoupled to the control circuit, wherein the position sensor isconfigured to measure a position of the displacement member, and a timercircuit coupled to the control circuit, wherein the timer circuit isconfigured to measure elapsed time, the method comprising: determining,by the control circuit, a position of the displacement member;determining, by the control circuit, a zone in which the displacementmember is located; and setting, by the control circuit, a directedvelocity of the displacement member based on the zone in which thedisplacement member is located.
 2. The method of claim 1, furthercomprising: receiving, by the position sensor, the position of thedisplacement member; receiving, by the timer circuit, elapsed time; andsetting, by the control circuit, duty cycle of the motor based on thezone in which the displacement member is located.
 3. The method of claim2, further comprising: determining, by the control circuit, an actualvelocity of the displacement member.
 4. The method of claim 3, furthercomprising: determining, by the control circuit, an error between thedirected velocity of the displacement member and the actual velocity ofthe displacement member.
 5. The method of claim 4, further comprising:setting, by the control circuit, a new directed velocity of thedisplacement member based on the error.
 6. The method of claim 4,wherein the error is based on at least one of a short term error (S),cumulative error (C), rate of change error (R), and number of overshootserror (N).
 7. The method of claim 1, wherein the surgical instrumentfurther comprises an end effector, wherein the displacement member isconfigured to translate within the end effector.
 8. A method ofadjusting velocity in a surgical instrument, the surgical instrumentcomprising a displacement member configured to translate within thesurgical instrument, a motor coupled to the displacement member totranslate the displacement member, a control circuit coupled to themotor, a position sensor coupled to the control circuit, wherein theposition sensor is configured to measure a position of the displacementmember, and a timer circuit coupled to the control circuit, wherein thetimer circuit is configured to measure elapsed time, the methodcomprising: setting, by the control circuit, a directed velocity of thedisplacement member; determining, by the control circuit, a position ofthe displacement member; determining, by the control circuit, actualvelocity of the displacement member; comparing, by the control circuit,the directed velocity of the displacement member to the actual velocityof the displacement member; determining, by the control circuit, anerror between the directed velocity of the displacement member to theactual velocity of the displacement member; and adjusting, by thecontrol circuit, the directed velocity of the displacement member basedon the error.
 9. The surgical instrument of claim 8, further comprising:comparing, by the control circuit, the error to an error threshold. 10.The method of claim 9, further comprising: maintaining, by the controlcircuit, the directed velocity of the displacement member when the erroris within the error threshold.
 11. The method of claim 9, furthercomprising: adjusting, by the control circuit, the directed velocity ofthe displacement member to change the directed velocity when the errorexceeds the error threshold.
 12. The method of claim 8, wherein theactual velocity of the displacement member is given by the followingexpression:${V_{DM} = {{A \cdot S} + {B \cdot {\sum C}} + {D \cdot \frac{\Delta\; R}{\Delta\; t}}}},$where: A, B, and D are coefficients; S is a short term error; C is acumulative error; and R is a rate of change error.
 13. The method ofclaim 8, wherein the surgical instrument comprises an end effector,wherein the displacement member is configured to translate within theend effector.
 14. A method of adjusting velocity in a surgicalinstrument, the surgical instrument comprising a displacement memberconfigured to translate within the surgical instrument, a motor coupledto the displacement member to translate the displacement member, acontrol circuit coupled to the motor, a position sensor coupled to thecontrol circuit, wherein the position sensor is configured to measure aposition of the displacement member, and a timer circuit coupled to thecontrol circuit, wherein the timer circuit is configured to measureelapsed time, the method comprising: setting, by the control circuit, adirected velocity of the displacement member; determining, by thecontrol circuit, a position of the displacement member; determining, bythe control circuit, actual velocity of the displacement member;comparing, by the control circuit, the directed velocity of thedisplacement member to the actual velocity of the displacement member;determining, by the control circuit, an error between the directedvelocity of the displacement member to the actual velocity of thedisplacement member; and adjusting, by the control circuit, the directedvelocity of the displacement member at a rate of change based on theerror.
 15. The method of claim 14, further comprising: comparing, by thecontrol circuit, the error to multiple error thresholds.
 16. The methodof claim 15, further comprising: adjusting, by the control circuit, thedirected velocity of the displacement member at multiple rates of changebased on the error.
 17. The method of claim 15, further comprising:comparing, by the control circuit, the error to a first error threshold;and maintaining, by the control circuit, the directed velocity of thedisplacement member when the error is within the first error threshold.18. The method of claim 17, further comprising: comparing, by thecontrol circuit, the error to a second error threshold; adjusting, bythe control circuit, the directed velocity of the displacement member ata first rate of change when the error exceeds the first error thresholdand is within the second error threshold.
 19. The method of claim 17,further comprising: comparing, by the control circuit, the error to asecond error threshold; adjusting, by the control circuit, the directedvelocity of the displacement member at a second rate of change when theerror exceeds both the first error threshold and the second errorthreshold.
 20. The method of claim 14, wherein the error is based on aPID error.